I know at R/C Unlimiteds, the FE rules allow:
1) Only three motors(NEU 1527 1.5Y 850KV, HET Typhoon 700-98 840KV, Turnigy SK3-3994 850KV)
2) Speed controller capable of handling at least 130 amps and 8S battery packs
3) Up to 8S packs but not to exceed 6000mAH. Battery type restrictions are LiPo up to 4.2 volts per cell, LiHV up to 4.35 volts per cell, both types with discharge levels between 30 and 60C constant
4) Props are limited to 57mm or smaller.
IIRC, these limits were set to keep the playing field relatively even while keeping costs down. It also limits the speeds the boats can attain since, unlike nitro or gas power, electric drive has full power at any RPM and requires no time to spool up. Using these rules, the FE boats are also comparable with what the nitro scales hit in speeds on our courses.
Just a little trivia, NAMBA is looking at using the R/CU rules organization wide since they seem to work well. If you want to read the full set of FE rules, they are located here:
Edited by Hydro Junkie, 25 March 2018 - 06:22 PM.