It takes me about 5 or 6 hours, working alone, with a rotary buffer to do my 30' boat below the rubrails when it is out of the water.
That's just for one step. I usually go back another day for the next step, and then apply the finish wax by hand. That takes about 2 to 3 hours.
I've all but given up using the rotary on the topsides because there are just too many areas that you have to do by hand anyway.
Having an assistant could possibly cut that time in half. Switching from spreading, to the machine, and back to buffing off the residue by hand takes a lot of time and involves a lot more up and down on the ladder.
Having an assistant who can use a rotary buffer would be even better because you could switch off every once in a while.