When I had my P-15, I made a modification to the Main sheet called a headknocker. Consists of a Ronstan RF-5 swivel block with becket attached to the boom at a convenient location. Here's the details... Run the main sheet as usual through the pulley at the factory traveler. then forward up the boom, through the Rf-5. This effectively removes the bridgedeck attachment and puts it above on the boom. Was very, very nice on the P-15. I know if I had an M-15, I'd make the same modification. Now, since that doesn't make alot of sence... simply Email me off list & I'll forward the picture... I made a second mod for the main & jib halyard using the RF-5. This also worked out wonderfully... Ask for that pic as well if interested.. Bill M-17 Tiperary San Francisco