Álex.b.g said:http://m.ebay.com/itm/SSS-56114-360KV-Brushless-Motor-6-Poles-For-RC-Marine-Boats-Surfboard-/282642479269?_trkparms=aid%253D222007%2526algo%253DSIM.MBE%2526ao%253D1%2526asc%253D20150519202348%2526meid%253D2c55fbaef20640a5afd5bacbb5557420%2526pid%253D100408%2526rk%253D18%2526rkt%253D25%2526sd%253D282624141010&_trksid=p2056116.c100408.m2460
The very basic thought behind a gearbox is this : The voltage is typically 50V to keeps Amps low , the RPM needs to be very roughly 3000 , now how many KV do you need ? 70Kv or so ( roughly) , who makes a 70Kv inrunner , and how smooth is that motor at startup and what size is that motor that must be dragged along under water . This is why everyone runs a gearbox currently. In one case i know, the guy runs a 2:1 gearbox and 90 degree drive , perhaps this will be the future or motor in the deck not in the Mast .