Originally Posted by PeterM
Risky moment here ....
I've not got one on my Avon ( despite being 'professionally' rigged from new) . I had one on the old boat that was painful due to corrosion when it wasn't looked after before I got it.
My car doesn't have one and it doesn't burst into flames , but of course when you crash a car one of the first things the fire & rescue ( can I call them brigade any more ? ) service do it cut the battery wires under the bonnet ( assuming its located there).
I think they can cause more hassle than is really worth it, but of course in the situations like Martini describes well worth it.
I wonder how many fires start due to dodgy switches etc .....
I'll get my coat .....
Stating the obvious..
The problem with heavy electrical cables coming direct from the motor to the battery, means that in the event of any fire whether it is caused by petrol or oil, once the flames get to grips with electrical stuff and a short occurs, the cables themselves short and spread the problem along the length of the vessel to wherever the battery is situated. With the electrics isolated at least it should hopefully be limited to the source of the problem. With a car you can stop, get out and walk to a safe distance and there are likely to be other people about to give assistance.