Optimist with Topsail and spinnaker - Extra sail area

[ollyp]

Hi

The optimist is the only dinghy we can take on our yacht however I have slightly grown out of it. I would like to put on a spinnaker, which has been done before. Also I would like to increase the sail area. To do I think that the best method would be to make a topsail with just over 1 meter square sail area. I thought I would attach a pole to the top of the mast and fill in the gap between the sprit and the pole but also go up a little bit higher.

I think I would have to rake the mast back massively or it would be extremely unbalanced so I will have the top sail tie of the normal sail attached around the pole or I won't fit under the boom.

Firstly will there be any issues in how the sail is balanced even when it is raked fully back? Also how would I work out the camber ratio and draft position for the topsail. Would I just make it like a normal sail except it is just a different shape or would I have to factor in other things. Also what would be an appropriate topsail size for a 60-80kg sailer?

Thanks in advance

Olly

 

[Seajet]

Olly,

your instincts are probably nature's way of telling you to get a Topper or Laser, proper boats rather than kiddie menaces with IS ram attack proclivities like Oppies...

The Topper in particular is a good boat, light and easily stowed onboard compared to an Optimist.

 

[ollyp]

Yes,
Don't worry I do now have a laser however I can't fit a laser on the coachroof on our yacht. It is very with the optimist anyway.

 

[Seajet]

I was thinking of a Topper - or maybe Laser - stowed on edge along the guardrails ?

Obviously it depends on what the mothership yot is, without knowing that I and others can't offer much help.

 

[Daydream believer]

Cadet every time

 

[Seajet]

And how does one stow a Cadet on a normal boat ?! Aren't they bermuda rigged and relatively deep hulled, so a long masty thingie ?

Might as well go for a Fireball...

 

[Seajet]

Or a Contender, that should keep you occupied...

 

[ollyp]

Our boat is a Beneteau Oceanis 361, however buying a topper is too expensive to justify and takes up too much deck space.

 

[Daydream believer]

And how does one stow a Cadet on a normal boat ?! Aren't they bermuda rigged and relatively deep hulled, so a long masty thingie ?
.

Well it is 8 inches shorter than a topper although 6 inches wider
A boat that can place a topper on deck can probably place a mast along the rail or up the main mast
& a cadet sails infinitely better than a topper
We had to get rid of the Oppies at our club as they could not beat the tide.
But the toppers are good for kids without any friends I would grant you

 

[dunedin]

a cadet sails infinitely better than a topper

Topper is faster than a Cadet according to RYA handicap numbers .... and certainly enjoyed by the junior racing fleets. And a lot easier and tougher to use and abuse on a yacht or beach. But both too big for OP space on deck

 

[Seajet]

Our boat is a Beneteau Oceanis 361, however buying a topper is too expensive to justify and takes up too much deck space.

I can't see how a Topper can take up too much space on a 361, I could probably carry a pair on my Anderson 22 if I wanted.

I can't think of a better boat for your requirements than a Topper, so stand by to fork out a few £ in the unlikely event I'm right for once !

 

[anoccasionalyachtsman]

I'd just get on and do it. Your upwind trim won't be affected that much by the topsail. If you're going to sew camber into it, just copy the top of the existing sail, but otherwise just play with the outhaul to get the draft right, again, match the main's draft where they meet, and aim for it to be slightly flatter at the top. (In the same way that all sails do to allow for increasing windspeed with height).

With the spinnaker you don't need to worry about fore and aft balance when you're going dead downwind so on that point of sail there would be no need for mast rake. As you come up closer to the wind the balance would suggest that you should be raking well aft, but bear in mind that nothing affects trim as much as body mass in an Oppie - you may find that the helm gets a bit heavy, but otherwise OKish. Again, I'd say just try it - you'll have a lot of fun.

 

[Seajet]

I'd just get on and do it. Your upwind trim won't be affected that much by the topsail. If you're going to sew camber into it, just copy the top of the existing sail, but otherwise just play with the outhaul to get the draft right, again, match the main's draft where they meet, and aim for it to be slightly flatter at the top. (In the same way that all sails do to allow for increasing windspeed with height).

With the spinnaker you don't need to worry about fore and aft balance when you're going dead downwind so on that point of sail there would be no need for mast rake. As you come up closer to the wind the balance would suggest that you should be raking well aft, but bear in mind that nothing affects trim as much as body mass in an Oppie - you may find that the helm gets a bit heavy, but otherwise OKish. Again, I'd say just try it - you'll have a lot of fun.

You're planning to stand by discreetly with a good video camera ready to dial straight to Youtube, aren't you ?!

 

[ollyp]

Thanks anoccasionalyachtsman, I will give that a try.

Will definitely upload to Youtube when finished.

 

[anoccasionalyachtsman]

You're planning to stand by discreetly with a good video camera ready to dial straight to Youtube, aren't you ?!

Most of my life has had some sort of project like this on the go - I just wish someone had filmed them. Mostly they were for my entertainment, but there were times when others got more than I did.

The Oppie careers of most sailors end when their boat is seen as too slow and too small and it lies collecting moss - before quietly being passed on. How much better it would be to able to say that you'd nearly hit 20 Knots in it before it all went wrong?

 

[Seajet]

Most of my life has had some sort of project like this on the go - I just wish someone had filmed them. Mostly they were for my entertainment, but there were times when others got more than I did.

The Oppie careers of most sailors end when their boat is seen as too slow and too small and it lies collecting moss - before quietly being passed on. How much better it would be to able to say that you'd nearly hit 20 Knots in it before it all went wrong?

The only way an Oppie will get near 20 knots is if it catches onto the fin of an Exocet sent by a flabberghasted yottie officer on a warship, pushed beyond his tether by the little sods tacking in front; or it could be scooped up and taken to 10,000' in a Hercules then dropped for the same reason, that should get it beyond 20 knots.

 

[alahol2]

Surely you could offer a tow in the A22 to allow him to achieve his life's ambition.

 

[TSB240]

Surely you could offer a tow in the A22 to allow him to achieve his life's ambition.

:encouragement:

 

[Daydream believer]

Topper is faster than a Cadet according to RYA handicap numbers .... and certainly enjoyed by the junior racing fleets. And a lot easier and tougher to use and abuse on a yacht or beach. But both too big for OP space on deck

I would agree with the second part of your post, but if one accepts the first part as being the criteria for a better sailing boat you would immediately kill the arguments the owners of Vancouvers, & the like, make for buying them

 

[TLouth7]

I fitted a Laser 3000 asymmetric spinnaker to an oppie. To get the extra mast length I swapped out the mast for a topper one - they split in half so wouldn't take up too much space on deck. The lower tube was sufficiently similar to an oppie mast that it fitted the step and gooseneck. The sail was then laced to the new mast.

I would suggest making a new sail that effectively incorporates the existing one and a topsail in one. This could use the sprit as a sort of full length batten to get a big roach.

One problem I found with the spinnaker was that the oppie hull, being rather small, lacked stability and I couldn't react quickly enough to the gusts to prevent the gunwale going under, being a little heavier than the intended occupant. The other problem was that with the kite's tack ten feet in front of the bow steering was rather difficult. To achieve balance would have required enough rake to bring the masthead behind the transom. A symmetric spinnaker of practical size would need some rake but probably not a ridiculous amount.

I would suggest focusing at first on getting a larger rig set up, I'm sure topper masts can be sourced reasonably easily (though check it would fit in your mast step). This would not require any permanent changes to the oppie, at least until after the experimental stage.

The obvious next step would be a trapeze...