Propshafts, presumably, had holes cut into bottom of hull at suitable size in line with motors,then couplings were installed to motors, and the shafts then epoxied into place.
Running 2x 545 motors, with Component Shop 12v 3700mah Ni-Mh, on 40mm props.
Reccomend bigger motors or water cooling because I had smoke pluming out of them the first and only time it has been run with the Ni-Mh. Before that it used a 12v 5ah jelly, which was too slow and on its way out anyway.
Aluminium sheet in hull is to support battery.