Tony - Stating the bleeding obvious, I guess there's two factors here: the heat of the flame and how much of that heat gets to the food. My MSR petrol stove boils water faster than my gas stoves so that would be my choice. I also use a windshield and, beneath the stove, a heat reflector, (both simple thick aluminium foil versions that came with the MSR) and that creates a "cosy" and hot environment for the pan - the difference is definitely noticeable.
All - I've just come back from a week's cruising the Solent with 4 of us aboard the BRe. We carried all our food apart from 2 suppers (I thought I wouldn't get away without taking the family out a couple of times!).
Thanks, Julian, for the tip about "Look What We Found". While not the cheapest option, LWWF was the tastiest, has a long use-by date (2017), is easier to pack than tins and the rubbish is also smaller and lighter. We also used Sainsbury's own-brand tinned curries, a tinned dhaal, and a chicken in white sauce and these were all good. We bought Sainsbury's ready-cooked packets of rice and mixed this with the curries and added a splash of water to make a 1 pan dish.
We also took a lot of "The Food Doctor" pitta bread because this lasts a few weeks and has high levels of protein/fibre, so is quite filling. Good at any time of the day: with jams, peanut butter, tuna mayo (small tins by John West proved useful) or with the evening meal. Naan bread typically has a 1 week use-by date so a couple of packs were taken to go with curry.
Sainsbury's also do a "Bacon Brunch" - foil wrapped pack of potato and bacon. Long sell-by date and while not healthy (or the best quality) it did make a good outdoor / camping breakfast. Can be bulked out further by mixing-in beaten eggs when the potato's finished frying.
Packs of Merchant Gourmet ready-cooked pulses worked well for lunch. Eat them on their own or mix through a small sachet of pesto and some chopped tomatoes and/or spring onions (in a plastic box, before sailing) for something even better. Their packets of quinoa, "wholesome mixed grains" and "spelt sun blush tomatoes" (latter doesn't need anything adding) all went down very well with the whole family. Sounds a bit trendy / poncy but tastes great, fills you up and is easily stored on a boat so I don't care!