Originally Posted by codprawn
I think our laws only apply to inland waterways but I am prob wrong.
Why LPG should be any worse than petrol vapour is beyond me.
It is because LPG is heavier than air and hangs around leading to problems if there is any static around.
In the US they have bilge blowers to clear petrol vapours before starting the engines.
In the UK, the gas stowage must be vented overboard from the lowest point, so it needs to be above the waterline.
I am not sure how far you would get on two portable cylinders. Consumption would be worse than petrol, since the cv is lower.