Angus99,
I found this True Induction brand model MD2B cooktop which Amazon says measures 20 1/2 wide X 14 deep. This might fit the space now occupied by my Seaward if it's the same size as your Princess. I'm not at my boat, so I don't know the exact measurements.
I stumbled across this YouTube vid of a DIY replacement of a gas range/oven with an induction cooktop and a convection only oven below.
https://youtu.be/SAz8O0brU8I