puertorican fishing boat, motor

A typical present day Puerto Rican fishing boat.

Just before leaving Salinas a friend let me know that a couple friends of hers wanted to charter my boat for a bit of adventure. I was not even half prepared for that kind of thing yet with the Oasis, but i could use a bit more pocket money so i agreed to take them to Vieques, where we were returning to do a last bit of packing at our house before continuing on upwind.

I had intended to sail from Salinas at dusk arriving at dawn at Vieques, which would have been about right with the normal trade winds, but it turned out to be one of those very unusual days of the year where the wind died away to almost nothing and stayed that way most of the night and into the morning making us sail at about swimming speed. I felt a bit bad for our guests, but they did want a sailing adventure, and with sailing you’ve got to flow with whatever Nature feels like at that moment. Turns out they were lezzies and basically spent the whole time spooning each other on the foredeck. Seemed to me like an expensive way to nap, but what do i know? They seemed to enjoy the time so that’s what matters.

Late morning having already decided to cut the distance down by changing route to Naguabo, where i had bought the boat, there was a fishing boat a half mile off, wrapping up their morning’s work. Then they came towards us, and once close, all big grins, and loudly recognising the local “Campeón”; the formidable boat that most people would bet on in the races. They knew something had changed though, but clearly they weren’t sailors because they were not sure what it was about the boat that made it look so different from before.

They want to give us fish. That time of day is the prelude to lunch so i gladly accept, but instead of getting almost alongside, they just throw us the fish from a few meters away. The fourth slippy fish i don’t manage to grab well enough and and ends up sinking to the bottom in the clear waters. It broke my heart to see the fish go to waste like that but before i could even persuade them that three were more than enough, already they had enthusiastically swung a replacement fish into the air, which i managed  not to drop this time.

This is why you never throw things on a boat.

Lunch was fish with fish because without a fridge, i was not going to see yet more wasted food, and so we were all fully stuffed with delicious fish to last us a while.

The wind having picked up to seven or eight knots allowed the boat to cover the remaining few miles at near top speed again.

Our guests had already alerted their pickup ride as to the change of plans and she met up with us soon after we anchored.

Don Gelo, the Oasis’ builder happened to be in Naguabo and so i brought him aboard so he could survey the modifications to the boat. Although he understood and approved of the changes it was apparent that he had mixed feelings about it. His ‘baby’ certainly did not the look the same anymore, and her racing days would be over..

On to Vieques, which proved to be a uneventful short passage of a few hours. In Vieques, we spent a few days sorting through our possesions that were still at the house and packing up what we would take with us towards Brasil. The rest got given away. There is a limited amount of room on any boat and so one has to be meticulous about not hanging on to anything that is not actually useful. Still, it pained me to have to triage out many of my books, even leaving behind some of my engineering textbooks. As it was, i managed to pare it down to three plastic boxes, two of which were near impossible to lift with just my most prized books. Even my tools got triaged, and i got rid of duplicate tools, but most stayed.

There are six equal size cargo bays that i built into the Oasis, so i took three; one for the 5500 watt generator, one for all my tools, and one for all my books. Apart from the computer, the bicycle, and a bag of clothes that is all i have. I pointed out to Christina the remaining three which would define the bulk of what she could take as well. When i saw her immense pile of stuff i told her she still had to halve it or it would not fit, but she brushed aside my comments and insisted to try anyways. Of course it did not fit at all, and she ‘cheated’ by jamming more stuff pretty much everywhere else in the boat too, even in the passageway and up forwards, but i had to put my foot down and categorically tell her that more stuff had to go, that it was a danger to us and the boat to have so much stuff as to not allow free movement and that there absolutely could not be weight up in the eyes of the boat, etc. So after much wrangling and harrumphing we finally managed to get the boat tolerably well stowed for the rest of the way.

In order to avoid overdosing readers on sexy mathematics i’ll introduce another theme in this blog at this stage; lessons on seamanship and boat handling.

But not to worry, there will be plenty more sexy maths in the next technical posts.

—*—

For all airplanes apart from the very lightest you are required by law to have lessons, flying hours and prove to someone who knows a thing or two about planes that you are up to it. For cars, it’s more or less the same.

For boats, as long as it’s for private use (in most places) you buy it, and you’re off!

I’m not saying that there should be legal restrictions imposed now, quite the contrary; the fact that you can build a boat in your backyard and go off sailing around the world without asking anyone whatsoever if that’s alright with them, is incredibly empowering and should not be restricted. Not now, not ever.

However, with great freedom also comes great responsibility, and i always strongly recommend that novices take the time effort and even extra money required to learn how to properly handle their boat. Operating a boat, especially a sailboat, is in the same category of skill level as flying an airplane. A motorboat may be simpler to operate than a sailboat, but is still far more dynamically complex than operating a car, due to it being on a fluid interface, not on un-moving land, and the standards ought to be just as high as for a car, too, because with even a small motorboat you can quite easily kill a bunch of people through a few moments of poor decisions.*

So often that one sees the most spectacular fails of seamanship, that Edward Allcard, the great British singlehander with the dry wit, coined a term for it; “Harbour sports”. Harbour sports is by far the best spectator sport that i know of, as we all stop what we’re doing, to observe -usually with much commentary and even gales of laughter- the latest seaside mash up of ineptitude and incompetence. Naturally, the competitors always take it very seriously. But unfortunately, these events stop being funny for everyone if and when they escalate to serious tragedy..

At any rate, there are two types of novice; those who take it seriously and go to the effort of learning how to properly use their new boat  with progressively more challenging sorties and exercises, and those who think they already know it all and unwittingly enroll themselves in a new kind of sport.

The former get respect.

–*–

So we’ll start with that most basic of things, tying the boat to the cleat at the dock. Seems too basic doesn’t it? Regrettably, i can walk down any dock and with one hundred per cent confidence say that almost no boat will be correctly tied. Oh, stop being so pedantic! But it is true, and when one considers how much money gets put into boats i would like to think that owners are at least a little bit concerned with the correct way to secure their property.

I must stress here that none of what i will say i have invented, rather these are all things that have been learnt the hard way over centuries and passed down. At some point though, a lot of it seems to have been forgotten.

In just a few minutes wandering the docks, i collected images the most shocking, of knot perversions. I was going to post them, for humour’s sake, but then decided not to on the odd chance one of the neighbouring yachts happen upon and recognise their own ties in my online mockery, which could be poor public relations. So instead i personally re-created a sanitized, moderate version of the archetypal monstrosity as “tied” by should know betters.

endles half hitches

If you don’t know how to tie a knot, tie a lot!

Hopefully, after reading on you will never commit such knotty crimes.

It is crucial to understand what a knot actually is; it must not only secure in the most reliable way possible, but must also be got free again. Not just got free, but got free no matter what and very quickly and easily.

Impossible to untie under strain cleat hitch

Hopeless!

No doubt the worst possible case of tying to a cleat wrong is to start with the end, instead of starting by placing the standing part (the part that will become taut) around the cleat first. This guarantees that with any load the line is quite impossible to free. Unfortunately, when a bystander helpfully ties one af your lines at the dock, there is a fifty fifty chance of them doing it backwards

—-*—-

In the following image sequence i demonstrate the correct method of tying to a cleat. The boat, and thus the load, is off to the right of the frame. Note the end of the line and my hand is on the opposite side of the load from the cleat.

starting to tie onto cleat

First turn around the far side of the cleat.

The first turn is always around the furthest side of the cleat to the load. This gives the highest initial friction and makes a jam least likely.

mostly tied to cleat

Along one side and start crossing over

The line goes along the side of the cleat to under the opposite horn and the first crossover begins.

tying to cleat

Adding figure eights

From this point on, the line is brought under, crosses over, under, crosses over, in a figure eight pattern.

tying more to cleat

Some more figure eights..

This is already enough wraps.

finishing the cleat hitch

Finishing off with one half hitch.

To secure the end, one and only one, half hitch, preferably following the same direction pattern as the previous figure eights, gets made.

This is the only way to tie to a cleat. The only valid variations are in the number of wraps. This is a judgment call; enough to properly secure the load, but not many more either. Two wraps in most cases already does the job, more than four is almost always too many. It depends on the material of the cleat and the rope. The single half hitch at the end is optional, depending on the situation, but when mooring to a dock, it is definitely recommended. Omitting the half hitch is for situations where the speed of release is of particular importance, such as for example, on the mainsheet.

The reason for the first leg up the side of the cleat being straight, rather than crossing over straight away, is so that a maximum amount of friction will be produced in the initial full wrap around the cleat. It will be seen that in this way the rope’s first contact with itself will be in the opposite direction to the load, so the friction will be greatest. If one starts straight away with the crossover, or if one were to complete a full wrap all the way around with no crossover , in both those cases the entry and exit parts of the line would both be travelling in the same direction in the case of slippage. It’s an odd/even topological rule. Therefore, it must be along one side only straight and then the figure eight crossover loops.

There is also another reason to not do a full wrap straight along both sides of the cleat; the taut part of the line if it goes slack, can then ride up on top of that first wrap, pinching it once the load comes back on, making it impossible to untie.

The effect of the figure eights is to pull the rope away from the danger of getting trapped under the taut part to ensure that the line can always be let off whenever required.

–*–

It is absolutely astounding to me how such a simple yet important thing can so consistently be done wrong, that i must go over it again to try and impress the lesson here.

So let’s go over the first approach again with these clear illustrations from this useful knot tying site;

approach cleat

From the load to the cleat

wrong side cleat

The wrong side of the cleat

Never on this side.

correct side cleat

The correct side is first wrap around the far side to the load.

Always round the back of the cleat first.

However, i do not agree with the rather excessive amount of wraps illustrated in that site. Also he recommends certain ways of dealing with the excess line after the cleat. Note that this only applies for the boat end, one should never leave more than a meter or two of extra rope at the dock end, as it is simply an invitation for petty thieves to slice off the excess and walk off with it. Rope is dear; keep most of it on the boat where crew can keep better watch on it. Also never tie the very end of the line to the boat, as in a situation requiring to suddenly slack off a bit on the mooring lines, crew will not be able to, without delay.

–*–

Some more points;

When heaving a line to people trying to help on the dock, always assume they will do it wrong and make a point of re-tying each and every line. A typical thing also is of overly helpful people wanting to pull in and adjust the lines themselves at the dock end. Make it extremely clear that you only want the end tied and that you will do all the adjusting from your – the boat – end.

If tying onto a cleat that already has someone else’s line on it, it is poor form to try and cleat over their cleat hitch. Apart from being a bit dis-courteous, when they leave, they will be forced to untie your line and then when they retie (if you’re lucky) they will almost certainly do it wrong.

bowline on cleat

Bowline on cleat cannot be slipped up and off

Avoid this by tying under everyone else, if at all possible. It is usual for mooring cleats to have a hole in the middle which facilitates this. However, do not use a bowline. The bowline is a valid knot but belongs to the family of knots that cannot be untied if there is tension on it. Better to use one or two round turns and a clove hitch, which can always be freed. Like this;

two round turns and a clove hitch on cleat

Two round turns and a clove hitch on cleat

If instead of cleats there are bollards the correct way to place loops over it is as follows;

polite bollard technique

Correct multiple lines to the same bollard

In this way each person can unslip their line without disturbing any of the others.

Gaff rig

Sailing out of Salinas with the new rig.

We have inherited, for better or worse, our ancient tribalisms and continue codifying them into sometimes baroque systems of absurd paperwork, bureaucracy and “borders” that to someone like me who has lived a bit of everywhere on this planet, just seems like unnecessary impediments to free living.

And so it is that sometimes one has to be tactical in one’s life strategy in order to achieve the desired translations.

Christina and i have a son, but she wanted a daughter, and two children seems fair enough so we were shooting for that.

While at it, might as well have him be born in Brasil as that would certainly help us establish ourselves there.

Tactics.

About half way through the boat work, she discovers she is pregnant. We had actually been trying to delay a conception still, but Nature is pretty effective.

At any rate this put an absolute time frame on everything. There was still plenty of work to do on the boat, plus the actual sailing there, so it certainly put the pressure on.

Did you know about the mayan calendar system to predict the day of the birth?

This was our experience with the birth of our son.

The modern medicine man counts forty weeks, 280 days from the last period to birth. The Mayan counted one tzolk’in, which is 13 x 20 = 260 days from the last missed period (ie when the woman realized she was pregnant). But a woman’s period should synchronyze with Luna’s  synodic period, which is 29 days 12 h 44 m 3 s, or ~29.5 days. So this means the Mayans would calculate for about nine extra days of gestation. Are the Mayans who had thousands of years of a culture which venerated keen observational skills, or the modern establishment which has only a couple centuries of experience and many instances of insisting they are right about things, which later turn out to be dangerously false,… right?

As the days passed from the officially approved ‘due date’ of our first son, the hysteria, hand waving, and theatrics increased daily to brain bursting levels. You’ve got to see the matasano! You’ve got to go to the sick house! You’re going to have to get induced! You’re going to DIE!! All these and more, were verbatim (apart from the use of the word ‘matasano’ or ‘sick house’) pronunciations of concern .

Nine days after the modern due date, or exactly on the mayan due date, our son was born, after a completely normal and natural labour. Christina pushed him out like a champion. In fact he was born under a palm tree in our garden, as Christina felt better outside. I’m sure the primal instincts developed over millions of years of evolution work better than any theories made up by academics, which incidentally, are almost all male.

Will the mayans also be right with our second child?

–*–

I made a dinghy to replace the one that i had made in Vieques that got stolen. I had designed it so it would fit across the deck just behind the cabin. That way it creates almost no windage and is at a convenient place for launching. Also its weight is well centered and as low down as possible, without actually being inside the boat. Dinghies on top of the coach roof is a clumsy design setup that should be avoided if at all possible because it adds weight high up, a lot of extra windage, forces the boom or sail up** and blocks off your view.

The scow shape is the logical design for maximizing stability and weight carrying capacity for a given maximum beam. It also maximizes the amount of boat that can be made out of the given material as well as being the easiest shape possible to build without being literally a box. The only curve is the rocker, but that is enough to make it go through the water tolerably well. Being just 6 mM plywood it is very light and easy to launch over the side. Each end has a watertight flotation box so it does not flood when launched bow or stern first.

Micro barge

Scow-barge type of dinghy.

I’m no stranger to dinghy theft, and so despite this being a scow barge design, that is, not exactly an attractive shape, and its mode of propulsion is sculling, which in Puerto Rico exactly two people know how to do (Ignacio on “Éspiritu Libre”, and myself) I was not going to be so naive as to think i could leave it unsecured.

Therefore, while we were still back in Vieques, i had chained the boat tightly to a stout tree, with a chain and padlock going through a hole in the keel (the painter hole). The keel is bonded on with epoxy and numerous screws. Therefore, only 3 options for the thief; cut down the tree, cut through the chain, or break off the keel.

Never underestimate the low, low levels to which some people can go. One day i go down to the boat and the dinghy is not there. Just the chain and padlock around the tree and some broken pieces of dinghy. They broke the keel in order to steal a boat they are incapable of using and which was very specifically made so as to not accept an outboard motor. I later got a tip (there are only 8000 people on the island of Vieques) that it was actually a cop that did it because “unauthorized boat storage” or some such pettiness. I was never able to confirm that, but having spent enough time in PR it seems a plausibility. Who knows. In hindsight, i guess it was probably just as well I hadn’t put that “Saw” ‘esque booby trap i had been fantasizing about in the dinghy …

–*–

So back to the story in Guayama; rushed trough the rest of the work, made another dinghy, sails re-made and plenty enough other details.

Then we sailed down to Salinas just west of the main entrance to the bay of Guayama. This is an excellent hurricane hole and the tranquil anchorage is full of cruising sailboats. As expected, i was able to put my new ‘floating workshop’ to use and did a few jobs on some of the other boats, which replenished the wallet somewhat.

Oasis Salinas

Rafted to a boat i remade a rudder for in Salinas.

Steve, a friendly neighbour on a pretty and immaculately kept 40 foot ketch, gave me a beautiful big two speed winch which i eventually bolted on the foredeck close to the mast, to pull the reef outhauls tight. It doubles as a capstan. A much appreciated gift!

But time was rushing by, Christina was already three months pregnant. I had not yet built the reef points, but if we didn’t start moving we would never make it in time, so we left Salinas and started sailing upwind.

–*–

** if a dinghy must be put on the cabin top, a loose footed sail (sans boom) that can just pass over the dinghy is a big advantage as not only it permits the foot of the sail back down, possibly even closing off the gap between sail and boat entirely (very efficient) , but it actually helps reduce the windage of the dinghy too, because the wind on the windward side of the sail is already slowed down. (circulation, remember?)

Downwash and tip vortex GIF

Stationary smoke wall shows the tip vortices as well as the downwash created by the passage of a lifting foil.

Induced drag , or vortex induced drag is a topic one often hears mentioned at the technical end of sailing enthusiast circles.

Induced drag is the energy cost of lift.

In this post I’ll elaborate a bit on the post of ‘How is lift made‘ of two weeks back as well as to lay some groundwork in place that will be useful in future posts that will attempt to correct some commonly held fallacies as to some of the implications of induced drag.

As i explained in the penultimate post, lift is produced by creating a pair of counter rotating vortices; one that is shed at the starting point, and one that is bound by the wing and travelling along with it. These vortices are created by the act of moving an inclined plane or streamlined plane through a fluid.

What i neglected to mention is that a free flying wing must have ends; i.e. it cannot be infinitely long. So what happens at the ends of the wing?

Since there is by definition a pressure difference across the thickness of any lifting wing (otherwise it would not be lifting!) , when one gets close to the ends, the higher pressure underneath tends to push the streamlines out towards the free area beyond the wing tip, and similarly, the lower pressure above the wing tends to pull in air from beyond the tip. Both of these together make the air curl around the end of the lifting foil, at the same time that the fluid particles are flowing aft. When looking at the streamlines it looks like they get twisted up around the tip of the wing. They carry on twisting behind the wing under the newly acquired momentum, forming a long contiuous vortex going back along the path of where the wing came.

tip vortex

Tip vortex streamlines

Kutta and Joukowski both discovered and defined the concept of circulation;

\Gamma = -\oint_C V\cdot{ds}

Now, Helmholtz’s theorems, state that  a vortex can never start or end within the fluid, apart from instantaneously when being formed; instead any vortex must either join up with itself forming a loop without ends, or terminate at a fluid boundary.

Putting this together, we realize that the circulation vortex that bounds the wing and the vortices being shed off the wings are one and the same. Then, remembering that a vortex cannot have an end, we follow these tip vortices back all the way to where the wing began its journey,… and where it left behind its starting vortex, and there, the tip vortices join up with the ends of the starting vortex.

So we see that there is no ‘end’, it is all actually one continuous rectangular vortex. One short side is where the trailing edge of the wing was at the beginning, the two longer, and continually lengthening, sides are the lines the wingtips traced out in space, and finally the other short side goes through the wing from tip to tip and moves along with it. This last is the “bound” vortex part of the total rectangular vortex ring, and the part that is actually creating the lift which is the always manifested by the moving of a bound vortex through the fluid.

Around the outside of this rectangle air is moving up, and within it is moving down. This downwards moving air is the air that the passage of the foil forced downwards, called the downwash.

Not only do the tip vortices not contribute any useful lift they took energy to create so represent lost energy for the plane. Also, the ‘spillage’ of air from the tip makes the foil less effective at accelerating air downwards, so represents a loss of lift too.

lift distribution and tip vortices

Lift distribution and trailing vortices  
source; Olivier Cleynen

wing rectangular vortex wake anatomy

The anatomy of a wing rectangular vortex wake .

So how does this tip vortex create the extra resistance?
It actually does not, at least not directly, what it does instead is induce the resistance by affecting the overall airflow over the wing. Think about this; the extra downwash attributable to the tip vortices does not contribute to lift, yet is causing air to sink more than if there were no tips ‘leaking’. This in turn means that the foil is continually forced to climb out of the hole it is creating for itself. Since lift is produced at right angles to the airflow and this airflow is pivoted downwards it means the lift force is rotated aft as compared to the direction normal to the axis of travel. This creates a component of the lift force to be adding itself to the rest of the drag.

Induced downwash

Downwash induced by the tip vortices negatively affect the orientation of the lift vector.

Now to quantize some of these concepts…

I will spare readers the full derivation of these equations, and just jump straight to the conclusions. For those interested in knowing more, wikipedia has a surprisingly thorough amount of information on this.

The Coefficient of lift of a foil is defined in the following dimensionless manner;

.                                                 C_L = \dfrac{F}{\frac{1}{2}\rho{SV^2}}

Where F is the lift force produced, \rho is fluid density, S is foil surface area, V is flow velocity, all in SI (standard international) units. The  C_L is a measure of how effective the foil is at producing lift.

And the coefficient of induced drag works out to be;

.                                                C_{D_i} = \dfrac{{C_L}^2}{\pi{e\Lambda}}

Where \Lambda   is the aspect ratio, the measure of how long and skinny the foil is (when looking down from and above on an airplane) and is;

.                                                \Lambda = \dfrac{b^2}{S}

where b is the span of the foil from tip to tip. e is the planform efficiency factor, which i will explain later but for now can be taken as 1 for the perfect elliptical surface area distribution.

So we see that the longer and skinnier (higher aspect ratio) the lower the induced drag. Also the lower the C_L the lower the aspect ratio, but squared.

Apologies for the late post. I normally attempt to publish on thursdays, but was counting on posting another video montage. However, i’m having technical issues with the video renderer, obliging me to write after all at the last moment.

—-*—-

The next few months at Guayama i spent changing the rig and making the boat livable.

A lot of the nativos don’t have floorboards; you just walk on the ballast itself, but the Oasis had floorboards fitted some years after being launched to make tacking faster. This is because when you tack the rail meat all leap down into the hole along with their sandbags and then climb out on the new windward side, but it is a long way up. You have to first heave the sandbag onto the deck and then climb out yourself, and this is easier if the hole is not so deep.

So i removed the floorboards and cut them such that they would fit just over the top of the ballast, for more living space, lowering it by 30 cM. Forward and aft there were no floorboards so i made them. The aft floorboards would become our bunk.

Floorboards

The blue floorboards are the original floorboards, recut to fit lower down and further forward. The paint on the hull shows where the floorboards used to be.

The Oasis is the only Puertorican Nativo which has the mast going through the deck , in front of the opening in the deck. All the others have the partners inside the hole, usually with a strap going across the aft side of the mast. This makes stepping the mast a lot easier, but would have forced me to rebuild the deck aft of the mast before being able to build up a cabin. The reason for this is that it is not good engineering to have the mast go through the cabin top, as it is much weaker than going through the deck which is an uninterrupted span across the boat.

As it was all i had to do was build up the cabin sides around the existing deck aperture and screw and glue to the existing coamings.

cabin sides

Cabin sides fixed to coamings

After this i was keen to not have beams eating into the little height i had so i made the rooftop out of three layers of 6 mM plywood glued and screwed together over three forms which i subsequently removed. These defined a variable crown rooftop increasing towards the stern significantly.

Building cabin trunk

Moulds for cabin roof.

Using this constuction method enabled me to build a rooftop with no beams at all and quite strong enough. Some may wonder why i didn’t just make the cabintop higher; the reason is because raising the boom makes you lose the most valuable part of the sail, the part that is low down, contributing lift with very little heeling moment. As is, i only raised the boom 25 cM at the gooseneck, although much more at the after end so the boom would not hit the water so easily.

As soon as the cabin was made the boat became an oven, so i quickly made two hatches to re establish the proper ventilation. I also painted over the grey deck paint which would get so hot as to be painful on the feet, with pure white. For boats in the tropics, there is really only one acceptable color; white. I know the glare is something awful, but it is unavoidable, as that is exactly the desired effect; reflect the incident sunlight back away, to keep the boat tolerably cool. The equation is very simple; the less glare, the more heat, and vice-versa and there is really no way around it. Just good sunglasses.

aft deck

My wife giving a hand painting the new hatch.

For unstepping the mast i used the mast of a sailboat that was sunk on the other side of the bay, heeled over at a sharp angle. I climbed up this mast, which was quite terrifying i must admit, and set up my block and tackle. Then by anchoring the Oasis with four anchors under the top of this makeshift crane i could pull my mast straight up and out of its hole. Unfortunately, the mast was stuck fast so hard that no amount of force would budge it. So i cut the mast near the heel and dealt with the heel later.

Of course all the hardware, being stainless steel in aluminium was welded tight. Very few screws came out intact, instead i broke them off, and some had to just be ground down. After leaving the mast as a bare pole, i cut 2.5 M off each end, leaving me the fattest part of the mast at the height of the partners. Oddly enough the fattest part had been a couple meters above deck.

For the ends i laminated up wooden plugs, carefully sculpted for a perfect fit. At the heel, a tenon sticks out that fits into a slot on the mast step. The top of this is sloped and liberally sealed with epoxy. A small hole allows any water to drain out of the mast. At the top the plug projects beyond the aluminium so i could shape the step that take the peak halyard and a sheave for the topsail halyard. Both of these were then glued and screwed in place.

rough plug

Building up the plug for the mast end.

mast plug shaped

Roughly shaped and fitted ready to be glued in place.

Mast end plug in place

The first step will take the peak halyard. The sheave slot will be for the topsail halyard. The topmost step is for the spinnaker halyard.

Mast end plug shaped

Shaped and sealed.

Mast end plug finished

Blends right in with the aluminium!

In all i removed almost 60 kg of weight from the top of the rig. Selling the aluminium and stainless paid for the few bits of new hardware i needed, namely the new norseman compression cones. The gaff added less than 12 kg to the top of the rig. So i think that demonstrates the fallacy of gaff rigs being top heavy! And it is not true to say that that is due to actually having cut down on sail area, because with the topsail, the boat has almost the same sail area as originally and the topsail yard will only add another 10 kg or so, and that is weight that  is there only when needed, and that in light wind.
I think this last point is extremely important to understand; marconi rigs reef only the fabric. All the spars are fixed. On a gaff rig the topsail yard is taken down when not in use, and the gaff itself gets succesively lower with each reef leaving a bare minimum of weight and windage up when the going gets tough.

Sewing a mast boot

Sewing up the mast boot with some black denim.

Mast boot

Just needs a coat of paint – make that 7 – and no more water come in.

mast boot

The finished boot

Another change was i eliminated the two internal halyards, routing everything outside of the mast and taking care to seal the mast up entirely. Although this adds a bit of windage it is not much in terms of total percentage and it makes for one less thing that can go wrong. Also it makes the boat almost uncapsizable; i did some righting moment estimates and with that kind of buoyant volume as soon as they go underwater the boat’s righting moment almost doubles, which is a great safety advantage, especially if you think about how unlikely it would be for a capsized boat to right itself with a hollow mast that is all flooded full of water..

Then i recut the sails using a favorite time saver; contact cement. To save effort i recycled all the corner pieces by cutting them out whole and transposing them to their new positions.

Checking the new sail plan

Raising the sail folded along the cut lines and viewing from afar allowed to double check that the measurements i had determined on the drawing board would indeed be correct.

Re-cutting a sail

A covered basketball court made an ideal place to work on the sails. All edges and corners were preserved and re-attached in their new positions saving an immense amount of work and money.

The boom also got cut by 2.5 M down from the original 11.3 m to 8.8 M. I also modified the gooseneck to allow the boom to be raised to an angle of around 60 degrees so that it could be used as a crane. This rounded out the boat well for earning money later as a “floating workshop” complete with generator, a large collection of woodworking tools and two cranes (the gaff and the boom) to move heavy objects or step-unstep masts. Not having a cockpit means that the entire stern of the boat is flat and uncluttered for working easily.

Oasis mast down

Oasis with mast down.
on one side a boat i was doing work on, on the other a boat i was lookin after and where we also temporarily lived.

Inside i made a galley that uses the entire beam of the boat under the companionway hatch (to vent out the heat and also so i would get standing headroom when cooking) with gymbaled stove and an adjustable angle cutting board. On a cruising boat the galley is the most important area to get right. Cooking at sea is always challenging so every effort should be made to ensure that the galley makes those daily hours as easy as possible.

Forward of this and up to the mast is the cargo area on either side all the way up to the deckhead, leaving a passage in the middle. This gives a good distribution of weight out of the ends of the boat.

The advantage with this sort of boat is that the modifications can be made rough and ready and it doesn’t clash with what is already there. if this were a fancy yacht with delicate wood trim etc, to keep the modifications on the level would require considerably more time and effort.

Supper after work

Christina makes us supper in the neighbour’s boat.