2010 Bayliner 175 port rear cushion removal

[guitarsnlikker]

I cannot find a way to remove this rear cushion. Starboard side just comes off but the port one is attached. It sits above the gas tank.I am unable to find any fasteners. Anybody know the trick?
Thanks.

 

[Bondo]

Ayuh,.... Are there any signs of what used to hold the other one down,..??

Can you get yer hand in the back, 'n feel forward under the stuck one,..??