The 1993 Carver 33 aft cabin is a lot different than a C Dory. I had an earlier version of the Carver 32 aft cabin which was one of 4 diesel powered which were built. Mine had a single 150 hp Volvo and a 7 KW Westerbeke generator. I suspect that your boat has 350 or 454 blocks, with gas generator from 5 to 7 KW, so that you can support a convection oven.
My RV has a High Pointe combination convection/microwave, which draws either 1200 or 1500 watts (not positive about the power requirement)--this probably would fit the dimensions of your microwave.
We also have a combination micro convection at our home (GE Profile over the range) and A Sharpe combo on the Holiday Rambler we recently sold). We also have a stacked convection/regular at home--and the convection is far better in this unit--which is 220 volts, and a lot higher amperage draw than the over the stove. It is great Oven. But my. wife rarely used the smaller convections. In both the RVs, we use a toaster over over the convection 80% of the time. The smaller convections just don't use a lot of power, and thus don't seem as good as the higher amperage draw.
You can get one of the counter top convection toaster ovens (basically a toaster over with a fan), for less than a built in. Also it probably will work better.