But seriously.. 13'11" is maximum with no TX numbers. If you had a motor you would need TX anyway.
Also. DO NOT get caught out after dark without a big bright flashlight. You can shine a big light on teh sail and be legal. Absolute legal is a 360 degree white lantern visible for three miles
You can put on red and green bow lights that cover 270 degrees and a white light that shows for the other 90 degrees and be legal too.
BUT...The big flashlight shining erratically on the sail is the very most visible defense against being smashed by somebody else....and the light emitted by teh sail with a flashlight glowing on it technically meets the rewuirements for 360 degree lighting.
Nobody ever had too much light on a crowded lake full of tired drunks.