Beginner rider 85 Kg
115 Liter JP Free Foil Board
NP Flight Foil 2019
General free riding, hopefully wave riding.

I have 4.5 Naish Chopper with a the 370 RDM Naish 60% carbon MAST. 45CM Extension. Boom 140 - 190.

The Chopper has a big wind range and the 4.5 Feels more towards a 5.0.

I was looking at a 5.7 Wave sail for lighter winds.

Hopefully with a luff I can fit on the 370 + 45cm extension.

I did want a sail with lighter sheeting pressure as Ive had tennis elbow problem from windsurfing in the past.

Cheers Every one.

Might be wrong but I have never seen a 5.7 wave sail that rigs on a 370 and 45 cm of ext. sounds a bit scary to me.

Never gonna happen on a 370. The most compact rigging sails are HSM QU4Ds and they only fit on a 370 up to 5.2

There are 5.7 wave sails now that you can rig on a 400 mast with a long extension, but not a 370.

FWIW, foiling is better with higher aspect (long mast, short boom) tight leech sails. So I'd consider freestyle sails instead.

Chopper XL (I think is the equivalent of about a 5.2 or so?) is probably the biggest thing you'll fit on a 370. I don't use mine quite as much any more but they are really good freeride foil sails. I could go from about 12 when using a fairly big wing. I tend to use a more high aspect no cam 5 batten freeride sail because sometimes speed is nice and while the Chopper is fun, aerodynamically, the fat head is a bit draggy. (Essentially, the Chopper is a sail with the top panel missing which doesn't contribute much to power but does help with the tip vortex).

Plus one for a considering a freestyle sail, too, if you need to keep the mast short. You'll get a lot of power in a small package.

I had a Chopper XL. Unfortunately Naish didn't actually give the area but when I laid it up against a 5.7 it was pretty close in area. The Naish was just short and fat. My XL rigged on a Naish Firestick 370.

I just got a 5.3 Chopper MKII. I have not used it foiling yet only landsailing so far. It's powerful but the boom is noticeably longer, the sail wont fit behind seats like the others do. I am hoping it will be my biggest sail. If so I will have three sails (3.7,4.5 and 5.3), ONE mast and one boom. We will see I still may add a 400 mast and get a freestyle sail. I basically wore out a 5.7 goya fringe that rigs on a 430. I sailed it a lot but now it's just more weight and size than I want and I just broke that mast.

Elbow problems come from overloading your tendons and ligaments.
Rig smaller for the wind conditions, hook in as often as possible, sheet out to unload arms.