Make sure the boats 230 V system cannot be fed by more than one power 
supply source at any one time (for example, shore supply, on-board generator, inverter) - a switchover system should be used.
Never use a domestic type plug on each end of a cable to connect between an inverter or generator and the boat's domestic sockets. With the inverter/generator operating and the cable plugged in to it, the plug pins at the other end of the cable would be live and present a high risk of electrocution.
If you run a generator on-board - to be protected by an RCD, a connection must be made between the boat's protective earth terminal and any generator earth terminal.
| If you are using a portable generator do not forget the serious risk from carbon monoxide poisoning |  |
If using a generator ashore - the same earth connection must be maintained and in turn connected to an earth spike (electrode) on the bank-side.
Using power tools
Power tools should preferably be "double insulated" and be marked as such.
It is recommended to use the shore supply to run power tools on shore rather than using a supply from on-board the boat, to ensure best earth protection.
Sparks from the power tool motors could ignite any flammable vapours; be careful where you use power tools.
Fire risks
If you are using petrol fuelled generator, remember the extra fire risks associated with the highly flammable fuel.
Refuel the generator ashore, never aboard.
Always turn the generator off before refuelling and put out all naked flames nearby.
Leaks, spills and vapour can ignite easily. Clean them up straight away and make sure filler caps are secure after refuelling.
Stow any generator having been fuelled in a self-draining locker, or on open deck where the heavier-than-air petrol vapours cannot flow into the boat's cabin or engine bay.
Store spare fuel in the same way and only undo the petrol container cap when you are well away from the boat.
Keep a routine eye on the condition of the fuel hoses, hose clips, fuel tank and carburettor. Spot any damage, deterioation and leaks early. Get problems fixed immediately and before using the equipment again.
See more fire safety advice here