HI Alan & Dave

I rather suspected that might be the case. I've trialled them in my Rib and they do work well so I'll just have to find a way of making the battery access easier!
Hope your beauty sleep wasn't to disturbed Dave

Thanks again to you both

Chris

HI Chris
Alan has just woken me up!
Apart from the brushless ESC's intended for car use on/off switches are not normally a feature of boat ESC's.
I very much doubt if you could add such a switch as the electronics is mostly sealed and on a very small circuit board. it's possible that this is not fitted due to interference with the water cooling or the possibility of water causing Irregular function.
I have used car types- they have a small fan on top of the ESC to keep things cool. Works OK for me up to the 35amp version and you can switch on/off easily.
That said I use LiPo batteries and always disconnect and remove from my models as soon as I finish sailing - I treasure my models too much to leave such a high power source in the hull when not sailing.
Like Alan says switches would need to carry very heavy currents and a good connector acts just as well, plus the contacts are cleaned with each connection.
I would add that I have seen many radio/ESC problems caused by unsuitable/faulty switches and personally prefer to unplug the battery rather than use a switch on all my models. As an additional bonus removing the battery prevents any leakage current due to wet connections causing damage to the wiring. 😀

HI Chris, not sure that there is a low current side on a brushless ESC without going into the electronics of one, I just unplug the batteries on my fast electric boats. if you put a switch on the cables going to the battery it would have to be capable of taking the amps that the motor will pull.
DaveM will probably give you more information as soon as he wakes up 😁

Alan