This toasting technique probably won't be much use on boats, but one of the first things I learnt at university in 1973 was how to toast crumpets on an electric wall fire, that being the standard heating the college provided. When it's off and cold, you twist paper clips around two of the horizontal metal wires of the safety guard, with one end sticking out, angled slightly upwards. So when a crumpet is pushed onto one or two of these paper clip ends, it stays on, and the fire will toast it. Watch it doesn't burn, remove and turn the crumpet halfway through, spread some butter on and that's it, lovely.
Some engineering student probably put quite a bit of thought into that design.
Nowadays I just have a toaster and use that.