Re: Sewing Machine: Long Arm worth the extra $?
You might want to clarify your post with the size of your boat.
I've never made or repaired sails. I'm DIY and have made cushions, biminis, dogers and covers with a standard sized industrial machines. Fabric management can be a hassle, and I think that fabric management could be mitigated by a long-arm machine.
For canvas, I think that I would prioritize a long-arm machine after a straight-stitch, rotary-hook compound walking-foot machine with servo motor.
I'm considering making sails and think that a walking-foot, multipoint, multistep zig-zag machine would be ideal. I passed up an almost new, very reasonably priced but still pricy machine and will probably end up with a well-used lower priced machine without these features. However, I have no intention to sew for profit.