WOW! That brings back memories.
Ian built a wooden board with a large copper tank (with a lid) and the hand pump. We got the ladies in the 'mess' to fill up a flask with boiling water, so when we pumped the boiler full, the water was hot. We were able to get the boat straight back on the water, but it took two or three laps to bring the boiler up to full pressure.
The only problem we had in the whole event was in the early hours, when the boat hit something underwater which damaged the steering servo. We managed to get it in and Ian and I changed the servo in minutes flat, without that we would have got past 45 miles. We did have a great time though.
Neil