fully battened mainsail?

[Birdseye]

I asked for comment on the yachting monthly board but so far 40 lookers and no reply. So maybe its a question for racers even though the intended use of my new boat is pottering with no long distance cruising and maybe just a few NHC races. But I am a sail tweeker keen to get the best out of the wind and the boat, so the question is whether thare are real benefits to a FB main.

From what I have seen the main benefit for a user like me would be the ease of hauling and dropping the main thanks to cars. The negatives are the extra cost £800? and the greater difficulty of de-powering

 

[RJJ]

I asked for comment on the yachting monthly board but so far 40 lookers and no reply. So maybe its a question for racers even though the intended use of my new boat is pottering with no long distance cruising and maybe just a few NHC races. But I am a sail tweeker keen to get the best out of the wind and the boat, so the question is whether thare are real benefits to a FB main.

From what I have seen the main benefit for a user like me would be the ease of hauling and dropping the main thanks to cars. The negatives are the extra cost £800? and the greater difficulty of de-powering

I am a fan. It's much more durable because (1) it tends to drop more evenly in the lazy bag, helping avoid bad creases (2) it flogs much less while hoisting/dropping or when tacking (3) when you drop it on the deck it's easier to roll into a stiff bundle until you can fold it correctly on the dock. Imho you easily earn the £800 back with an extra season or two of life in the sail.

It also holds its shape better in light airs.

You can add some extra roach if the backstay allows, good for light winds. The Cunningham becomes a more important control, a la windsurfing.

I don't think the depowering issue is an issue as long as you can flatten the sail well. The trend in big boat racing has been long top battens and square tops (like a big roach) for extra sail area in light airs and downwind, with powerful sail controls (Cunningham?) to twist off the head. With full battens, twisting off the head leaves it streaming stiffly to leeward rather than flogging around, which is much better for depowering.

In any case, just reef earlier.

The other negative you didn't mention: increased weight aloft, and also when lugging the sail around.

 

[Ceirwan]

My boat came with a fully battened main.

You're correct in that it is slightly less tuneable, I've never had issues depowering it per-say, you can always dump the sheet & being fully battened it just sits pretty docilely rather than crashing about the way a normal one would.
But you are a little more limited with how far you can tune the shape, and twisting off the top section in a blow doesn't seem to be as easy.
Its still very tweakable though.

Short handed its a nice thing to have, going head to wind is pretty much drama free, I don't have cars, just sliders & it still goes up and down easily (smaller boat though), also nice when flaking as it keeps the main tidier.

I'm not sure if I'd specify one, over say a normal main with full length top batten, but I've certainly not felt the need to get rid of it.

 

[TLouth7]

Do you have a fractional rig with the realistic ability to adjust mast bend?

 

[Birdseye]

Yes, its a fractional rig for a change and I was looking forward to being able to depower the top of the sail. I wonder if you can go half half ie short batten at the top and FB for the rest?

 

[Ceirwan]

Yes, its a fractional rig for a change and I was looking forward to being able to depower the top of the sail. I wonder if you can go half half ie short batten at the top and FB for the rest?

The opposite is normal, full length top batten to get some extra roach & the rest just partial.

 

[TLouth7]

Bending the mast will flatten a fully battened sail. Think of it as moving the middle of the mast forwards relative to a straight line between the base and the top of the mast; this will allow the battens to straighten.

Increasing twist in the normal way is very effective with a full top batten because the batten retains the shape of the top of the sail even as it luffs slightly.