well not having alot of test and tune with boat really playing with the swordfish data logger, now its down to buisness i have been using a detounge x442 and would say the boat is hi 30 low 40 with the crap batteries- going with the dinolgy batts asap. motor and esc always low temps battery is what gets warm/ hot. what would be max prop for ul-1 motor, i was going to get the cnc 43mm and 44mm and have not looked into grim props yet , i have x445,m545,m645