Have a 2001 Chapparal 296 ssi. There is a bench seat running along the back that is split. There is a long hinged cushion in the center and 2 removable cushions on each side. There is no walkway thru the sun deck so you have to step on the cushions to get in the boat. The problem is if you step on either side cushion it slips off the lip(which is a thin strip) it rests on and you fall in the the storage bin below. It is starting to rip the vinyl and I am worried someone will get hurt. Any suggestions on how to keep the cushion On the lip or how to extend it?