I am a big fan of convection ovens and microwaves, but..... A convection oven is great for items that need long cooking times, Turkey comes to mind, and you just don't want to spend a great deal of time cooking. So a 12 pound turkey done in a convection oven will take around 2 hours 15 minutes, much faster than conventional roasting. But how often are you going to do a turkey, and why not just get a turkey cut in half, one for the boat, one for the home freezer for further consumption latter on.
The microwave, this one I find more interesting. My boat is in refit and I told my guy I wanted a microwave. His response: "Rick, I'll put one in if you want but we have one in our boat and we just don't use it that much." Of course living in a commonwealth - Canadian here - there is God, Country, the Queen, and now of course the microwave. What I decided to do was watch how I and my wife used the microwave to see patterns. As you can guess, the great majority of what we did was re-heating of liquids and food. And can this be replaced by the stove, oven and barbecue?
So lets take popcorn in the microwave. If you are like me, you aren't a fan of how your house or boat smells after using the microwave popcorn bags. Now I'm going to sound like an old fart: "In the old days...." you took a large pot, added some oil, put in the popcorn kernels and voila - popcorn. You don't need a microwave and your boat will smell better.
You don't need your microwave for reheating. That spaghetti heated up in the microwave can just as easily be put in a pot and gently heated up. Heat kills coffee so you are better off saving hot coffee in a thermos, in fact, better coffee makers now use an insulated, double vacuum wall carafe rather than a heating plate to keep the coffee warm, rather than kill the coffee with heat.
What we Northerner's call a barbecue, isn't. A true barbecue cooks things at a long slow temperature, liked pulled pork, for instance. Our northern barbecues are really grille and oven. And I have used a barbecue to cook the turkey, just not on a boat. My favourite, any idiot can do it, is beer can chicken but instead of beer, I use Seattle Market Spice Tea with water which when steaming, gives the interior of the chicken a very gentle hint of orange. The outside of the chicken is painted with a wet rub of light tasting olive oil and Montreal Steak rub, great on chicken. The chicken comes out looking great, tasting great, and you look like a genius. Weber makes the best beer can chicken cooking utensil, pricey but great - don't wash it in a dishwasher, trust me.
One of the aspects I like about boating is the slowing down of life and I realize that a microwave on the water really isn't needed, I'm not going anywhere fast anyway. So sip a gin and tonic (with lime please), warm up the spaghetti in a pot to eat with your beer can chicken.
I told the refit guy he was right, don't install a microwave, now a toaster, that's different.