hello,
I am in the process of ordering a new overlapping headsail for a triton 24 (except if some of you have one for me...).
Really hesitating on the tack height above deck, at the moment I have a really high cut jib (tack height probably around 50cm), good for visibility but the gap without canvas seams too important.
If I well understood, a deck scrapping jib is more performant with more surface, prevent turbulent flow at the foot, lower the heeling force (Am I right?)

Does it mean tack height should be 0 (just a shackle)?
What would be the best compromise between performance and reduced chafe on the life line (for coastal cruising)?

thks

Without getting too technical, if your tack point is level with the top lifeline (as per a furler), then the clew should be just above or below the lifeline when it gets winched in.
Save the deck sweepers for a racing boat. They are way too much work, as you need a dedicated body just to skirt every time you tack (but you can be lucky and bounce it over sometimes). Rollers work sometimes as well.
If you are not racing, then put some white plastic protectors over your lifelines.
Best performance will be from a new or near new sail. Preferably cut to size for your boat. Anything else will degrade performance, even if only slightly. If it is being made for you, ask the sailmaker for his opinion based you what you are going to do with it.

EC is spot on, tack height (and clew height) are dictated by the role of the boat in your life!
If you are after practicality/ ease of function/ safety and sail shorthanded then the high cut is for you.
Improved visibility, no skirting of foot when tacking and less movement of genoa car position when reefing on a furler.
Low cut sails do have better performance so if you are of a racing bent then look at that.

Hey cazou
Not many here realise how important is getting right, simply, they have larger boats.
After cyclon Marcia, I load mast and head sail. New headsail was cut using a pieces of old one.
My new sail tack was really high. see pic. I lost soo much air above cabin that, she didn't go and lean a lot.
Took me 6 month to get recut, what a magic happend, she flyes now, it's soo good that 90% I don't bother with main.
In my case it's extremely critical, Aquarius 23 doesn't have drop keel , but buil in very shallow and centreboard .
Any loss of air above cabin is very critical, I have oversize headsail with tuck about 30cm above safety lines.
This picture is before re cut.Sure I lost about 1/2 meter on top, but it feels she is more stable .

thks a lot for the advices,
I found an old brochure of the triton 24,
clearly bigger and lower headsail than what I have,
As charriot says, on such small boat where the head is the main power, loosing 1m of canvas at the foot still seams too much a compromise for me