windsurf to Sailboat

I am in mid fifties and used to windsurf until about 10 years ago in my free time. I would pack my gear on top of my car and drive to lakes or shores of my land and windsurf couple of hours. Lakes were easy but the shores were open to seas like Mediterranean, Aegean and Black sea winds. Then a doctor told me to stop because I had low back problems. So I stopped but I still remember my good memories of planning between waves and sailing with some speed and miss it so much.

I was able to use my trapese when the wind was strong enough, but I never learned waterstart. So, pulling the sail from the water was heavy on my back and that is the reason why I stopped.

Now I have seen some small boats with fixed masts like trimarans, cherubs, paper jets, moths, contender skiffs, ICs ect and started wondering if I could transform my windsurf board to something to be:

Transportable on top or back of my car.
Not so heavy,
Fixed mast

My board is still in good condition.
Mistral Ventura
Length: 320 cm
Beam: 65 cm
Hight: 15 cm
Weight: 15 kg
Volume: 160 liters

My own weight is 72 kg

Board is constructed with foam inside, LCS: Light Compound System, probably fiber-epoksy of some type.
There are 6 foot straps, each using 4 screws. The screws are 3.5mm X 16 mm each, these can be used to install a metal or wood frame.

Mast foot can be adjusted on the length of the board anywhere for 45 cm. If needed I can cut the board and install anything anywhere too.

My sail was 6.4 meter square but the monofoil got busted. Maybe I can repair it using Tyvek or make an entirely new one. I have another sail which was smaller, a friend will return it to me, which was 4.5 meter square I guess. In good condition.

I can use my mast or make a new mast and sail of any dimensions. I am planning to fix the mast down to boat by felxible wires, so that the windsurf will be something like a sailboat. I can make a rudder, use or modify existing fin and daggerboard (centerboard) that is foldable type to inside the board. I can add wings like international moths or I can add amas to transform the board to a trimaran. When I stand on my board, it is quite stable without the mast and sail and can be used as paddleboard. I plan to sit somewhere or use trapese or lean out on it if I add wings.

I do not mind getting wet, my winter wetsuit is still fine.

My aim is:
If possible to make a sailboat from my existing board and gear.
It should be taken apart and be transported to different locations on top or behind my car on a dolly.
Each part to carry should be maximum 30 kg or less,
If possible the sailboat should be able to plan

I do not care for racing, I do not care for how it looks ugly or not. But I care if it can sail upwind or downwind to wherever I want to go.

I have hand tools and being working with Aluminium and wood, have a simple sewing machine for making sails or repairing, I can also learn and use welding and epoxy techniques if necessary.

Picture is from web, showing the board and parts,

 

Daggerboard, mast foot system, again from web, but similar to mine.

Bottom of the board is flat, bouyancy is regular and kind of uniformly distributed from the tip to the back,

 

The simple answer is no, or at least not well. The requirements for a good sailboat, both in rig and hull, are very different from those of a good board. Even taking a board rig and planting it on a boat hull doesn't seem to work well.

 

The answer is yes.
I have a link and reference/ picture to a Scotsman who did it.
Basically he used a wood kayak for the hull, and a windsurfer rig.

I'll try to get it tonight.

 

The Ventura will be slow and very hard to sail as a dinghy. It is very narrow and short for a dinghy, and extremely narrow for a low-freeboard dinghy. It was not designed to be sailed heeled at low or medium speeds. If it heels like a dinghy does, those characteristic '80s rails will slice into the water, allowing it to sink sideways.

You will also find it very hard to affix a rudder, and because an effective rudder is much larger than a windsurfer fin the board will not balance properly.

Other big problems will be the weight of the added fittings like wings and a rudder mounting, and working out how to attach such fittings without crushing the skin and the low-density foam underneath.

You'd be much better off with a dinghy hull. The windsurfer rig is certainly not ideal but it could be the basis of something that would work a bit.

 

I had a 12 ft flatty once which can be built with 2 sheets of ply. I put a windsurfer rig on it. It planed with me and 2 children onboard.

 

Yencie,

Here is the boat built from a kayak and a windsurfer. I think the board will not be usable as was said above.



Here is the web page: http://www.etiennemuller.com/trimaranrigged/index.html
There is also a build log.

I made a mistake, he is Irish not Scottish Please don't let him know I said that.

 

Thank you everybody for the comments and the time.

I found one person who has done some work on a similar situation who has about the same age and requirements like me:

http://smalltrimarans.com/blog/unique-small-trimaran-under-development-part-3/
Here he has 12 objectives that are also mostly what I could think for myself.
Comments to this page has also some more ideas that could lead to a simplified version of SailRocket. My board with a windsurf sail attached to it leaning on an angle as if a windsurfer has got it, but with a wire. A beam attaches the windsurf to a kayak or anything with a flat bottom in which I sit down, controlling the ride. I would be happy to sail with maximum 10 knots, if it planes, not trying to break any limits. This would be single sail.

He already looks like has started to plane.
http://smalltrimarans.com/blog/very-unique-small-trimaran-approach-part-4/
http://smalltrimarans.com/blog/very-unique-small-trimaran-approach-part-5/

The designs below may show more what I meant above:
http://webspace.webring.com/people/na/aerohydro/othercrafttext1.htm
http://webspace.webring.com/people/na/aerohydro/home.htm

 

Yencie,

The last reference is great. Thanks for posting it.
But all those boats look like a young mans sport.

Interesting that one of the boats was measured at 27 kts. An old style Tornado was measured at ~26kts on a race course (old report).

 

I know that board well (I own one of the lighter versions from the same mould) and it's a long, long way from planing in any of those pics.

If the builder is having fun with the little tri that's great. Little tris are bags of fun. However, his claims that it has unusually good performance appear to be pretty odd, although it may just be that he counts close reaching as going upwind.

Compared to the original craft, he has;

* Increased the weight by about 3 times;
* Gone from a rig designed for maximum possible all-weather speed, to rigs designed to be easy for children to use, and possibly much smaller than the original;
* Increased wetted surface and reduced the efficiency of the main hull shape dramatically by adding the floats, rudder and a lot of weight;
* Increased the wetted surface of the main hull significantly, by reducing the ability to "rail" the board upwind and to lift the bow by sliding the mast track downwind;
* Lost the advantage of "closing the gap" and the advantages (if any) of a vertical leach and rig raked to windward.
* Lost the dramatic increase in righting moment caused by the sailor and rig leaning to windward.

He has gained a bit more lateral resistance. Overall it adds up to a craft that is significantly slower than the original Superlight II, which was very roughly about as fast as a Laser upwind in the conditions in the photo*, so it's hard to see why it is now "unusually quick" as he claims. If you take something about as fast as a Laser in certain conditions and modify it to take away efficiency and add lots of weight you don't make something "unusually quick" in those conditions.

All those effects would be much more pronounced on a shorter board like the Ventura. It's hard to see how it would be anything other than unusually slow most of the time, compared to a typical small boat like a Laser.

Of course, it's all about having fun and if you have fun that's wonderful. It's just that the claims of performance appear a bit ambitious.

* In other conditions, the Superlight II was really, really fast and could beat big cats and skiffs. It's just that no Raceboard was really quick upwind in light winds unless the wind was very steady or you could foot into big headers.

 

I think there's a lot to be said for the canoe style approach for a lightweight recreational craft, be it trimaran style, or simply a plain canoe with a small rig to suit the lack of righting moment. In many ways a Canoe you can still paddle, but has a daggerboard and a rudder so you can sail it properly might be best. After all a trimaran probably weighs at least twice as much as a single hull Canoe, so you've inherently brought yourself a lot of weight and complexity.

The other month I was watching someone rig and test sail a commercial trimaran/canoe, and it was horribly time consuming to rig and complicated to get into, and it struck me that a simple canoe with a smaller rig would actually be more fun and so much less trouble. Drop in daggerboard, drop in mast and sails, and off you go.

If it had the old US style canoe rig of a unstayed masts near the ends then the sailor could be seated in the middle with their head clear of any booms, and you could even keep the paddle on board so you can paddle up a river if you need to.

A canoe won't really plane, but it will slip though the water well enough...

 

Ok what about a version of a this fliptacker design?
http://webspace.webring.com/people/na/aerohydro/othercraftframeset.htm

Or a rocketsail configuration of some sort as in attached picture. My surf board has a fin and daggerboard that I can also easily increase in lateral area if needed. Consider I use my board on the left hand side, and stay on it. The sail is on the right hand side with a smaller board holding it on water. Since I am no more near the sail, smaller volume and light board can hold the sail alone. The increased beam weights can be (maybe) compensated by increasing sail area. I was windsurfing with 6.5 square meter and planning, maybe I could use for example 10 square meter to compensate the added weight of the rigs and the small board. But the problem I see in this device is that it can not be sailed when the wind is on the opposite side. It looks like it needs to be sailed always the wind on one side. The fliptacker link above seems to overcome this problem by swinging the rig from side to side and using a symmetrical sail.

 

See if you can find a copy of High Performance Sailing by Frank Bethwaite. FB was arguably the foremost sailboat researcher of the last 50 years, and he ran an extensive and long term project on unconventional boats, starting out with various proas, inclined rigs, and so on, not wholly unlike what you've drawn, and with the Bernard Smith work as a starting point.

The complete "High Speed Project" ran to some 20 boats but the eventual culmination was a relatively conventional trimaran type with a centre hull and rig reminiscent of a long thin 49er, and outer floats which were intended to be kept clear of the water when possible. He found that the inclined rigs and proas and the like simply did not provide a satisfactory sailing experience.

If what you want to do is to construct unconventional craft and learn from what you're doing, and not worry too much about how much sailing you do (probably very little!) then by all means go down the experimental route, and appreciate the frustrations and irritations along the way as a necessary adjunct to the pleasure of doing it. But if you primarily just want to go sailing its probably best to learn from Bethwaite's experience. A good question to ask is always how much time on the water have these various craft actually achieved...

I remember being rather negative about the Sailrocket project when it started out, and I think I was both right and wrong. Right in that the performance of their original craft/configuration topped out in the rather disappointing sort of range I thought it might. Wrong in that, having seen a number of such projects sputter out after a couple of seasons disappointment, I utterly failed to appreciate just how much energy, commitment, time, yes and money Paul Larsen and Helena Darvid were going to put into their project over eleven years or so. They thoroughly deserve their triumph, but don't underestimate the difficulty of getting something like that working.

 

If I put aside my old dear windsurf board and sail and think of the whole thing over, prefer to do more sailing without any trial-error process, what type of sailboats could be fun for me?

When I look myself, the following boats seem to me like a lot of fun, but I have no idea how hard it would be for me to ride one
Maybe with smaller sail area and compromiss on planning speeds in the beginning.
http://www.uk-cherub.org/doku.php/boats/boats
On the other hand, 70 kg of weight still seems a lot to me.
Actually, everything after windsurf seems enormous to me anyway.

As I said before, I am over 50 years and have a low back problem,
I like to bring the set with my car, limiting the length to 4.5 meters if on top.
Using a dolly could also be considered in case of no other option possible.

Paddling is not what I like, I have done a lot of it when I was a child to know.

What would be the designs preferable for me single handed?
What options could you recommend if I sail together with my friend?

 

If you are still willing to do some construction I suggest the Trika 540.
Cartoppable, works as a kayak also, intended for 2.
Available as a kit, so less work.
http://www.dixdesign.com/Trika_540.htm