I bought a round Magma last season. The round post mount was easily installed on the swim platform of my Sundeck. The grill and its post stow easily in an onboard compartment.
The grill is less effective on windy days but so far has easily cooked hamburgers, hot dogs and sausages. I have yet to try to cook a steak of any fish.
Cooking aboard requires a few untensils that, if forgotten, can make for interesting times. DAMHIK...
I bought mine on Amazon for significantly less than local sources. Before I get pilloried for "not supporting" local businesses, rest assured, they get a significant cut of my boating budget.