As Chris said, open everything that can be opened, unscrew any fixed floorboards. If you have power, and access to an electric dehumidifier, that is a good idea, preferably with the water drain going out through the sink drain, instead of filling up the internal reservoir. You could even put another ventilator to blow air under the floor boards.
Thank you for replies – we are here at moment. Can’t take any more of floor up but have got most of water out.
Only concern is when some water was spilt in one of the cupboards, it drained away instantly but don’t know where?? Engine compartment maybe. Need to get in there next. Should we be worried about there being water anywhere else i.e. in the bilge? Don’t know how to access this – novices here!