Mainsail Trim

Hi all,

New to Hobie 16 this summer, long time sailor. I've now had my 2005 H16 out in a variety of conditions and the one constant is that I can't seem to get the main set quite right. When I have the boat so that the main feels right (just to my gut feel), the windward telltales in the luff of the sail are flapping. It's not extreme but certainly a sign to me that the leading edge of the sail is not trimmed in enough for the point of sailing. Meanwhile the trailing edge leech telltales are wrapped around to the leeward side indicating that the main is over trimmed for the point of sailing. I just cannot seem to get both the forward and trailing telltales to flow nicely at the same time. This is true on all points of sail. And I assume this is preventing me from pointing as well as I should be able to do so.

Vertically the telltales seem to be doing about the same at all levels so I don't think the problem is one of twist. I think the problem might be one of too much belly in the sail. But I'm not sure.

Should I go more extreme on the downhaul? I'm already at the point where the boom is at the black tape mark on the mast. And it's quite difficult to get any more downhaul. To get more I think I'd need to put my feet against the mast and pull back. I do put the downhaul on before I tension the jib halyard. I'm concerned about breaking something with more jib tension.

Or is this simply a matter of the sails being 10 years old? Would new sails have less of a belly?

Or have I missed the problem altogether?

Thanks in advance,

NAM

I'm new to sailing at all, but just to throw it out to you what about how tight are your battens? I would think that would have an impact on belly of the sail? also I'd think on a factory "Hobie" sail ten years would be nothing, but conditions and care I'm sure are factors on sail life. My boat still has the sail it came with and is from the 70's I think.

You indicate "all points if sail". The description may be loose or missing (?) battens or a worn out sail, but that would surprise me for a 2005 unless the sails were from an older boat. The downhaul needs only to be tight enough to take out the wrinkles in the luff. If your mainsheet is pulled in where the blocks are almost touching, I don't see how a good sail would allow a belly like you're describing. I'd like to hear what mbounds. srm or one of the other experts have to say.

I'm not an H16 expert, but one thing I'd check is to be sure the mast is not over-rotating past the stops.

Downhaul can take the belly out of the sail, but that may not be the issue.

I usually steer by the jib tell-tales (be sure your jib is properly trimmed) and then trim the main to keep the leach tell-tales on the main flowing 90% of the time. Because of the wing-mast design, I've found the windward telltales up by the mast often flutter quite a bit. I wouldn't worry about this too much if the jib telltales are correct.

_________________
Jeff R
'88 H18 Jolly Mon
'10 F18 Closely Called
cramsailing.com

This could be a longshot from a true nube, but are the tell tales on the main the right distance from the mast? I read on the H16 Forums that the main tell tales were supposed to be 18-24" from the mast. But after reading Rick White's excellent book "Catamaran Racing for the 90's" I moved my tell tales much closer to the mast. It was a mistake. Because of the mast profile and rotation, my main telltales looked like you were describing. Some experienced Hobie sailors told me afterwards that Rick White's suggestions made more sense for other catarmarans, but not the H16. So if the tell-tales are too far forward, they'll act strange even if you have the main trimmed right.