This is from the E-R/C Unlimiteds rule book:
▪The only power source shall be up to 12 sub‐c battery cells of NiCd or NiMH chemistry, or up to 4S configured Lithium Polymer (LiPo) battery(s). The total capacity of batteries in the allowed chemistries and configurations shall not exceed a total capacity rating of 6,000 mAH and a total fully charged voltage of 16.8 voltsDC. • Only LiPo batteries with a manufacturer’s maximum discharge rate of 20C or greater shall be allowed for manufacturer’s rated capacities less than 4,000 mAH and a manufacturer’s maximum discharge rate of 15C or greater shall be allowed for manufacturer’s rated capacities of 4,000 mAH andup. ▪Power shall be provided by a single motor limited to one of the following currently approved motors.
NAMBA‐approved motors
- AquaCraft AQUG7000 L36/56 7.2‐18V – 6 pole brushless
- Himax HB3630 1500 brushless – 6 pole brushless
- ProBoat PRB3310 A3630‐1500 – 6 pole brushless
- DYNM3835 A3630‐1500kv, 6‐pole, Water Cooled, Marine Motor
No modifications are allowed to the motor except for except for normal wear, drive flats or keys, electrical connectors and water cooling, it must be run as shipped from the manufacturer.
Bearings may be replaced at any time.
I'm not an electric drive expert but the above should work since they are used for racing 1/10 scale boats which are slighty smaller. Since you've said you're not going to be racing, that shouldn't be a problem. One thing that would be a problem is using a 6000RPM motor. Hydroplanes need a high speed motor as the prop is what lifts the rear of the boat. Lift is provided by a combination of the prop blades entering the water and the drag from the blade shape. The "roostertail" you see behind the boat is from the prop blades leaving the water since, when the boat is on plane, only the bottom half of the prop is in the water.
Just out of curiosity, Colman11040, did you see the picture of my boat back in Post 5? That thing is a giant compared to the Miss Unlimited and requires over twice the power to get it to run properly. Add to that the fact I've been building and racing these things since 1982 AND have worked on some of the full sized boats, I'd say I know a thing or two about them