It depends on what type of test system you use I persume you are using the MENSA IQ scale 100 being the average I do not think your plan to use a Boat on the humber is viable. As you would have to kill the captan and crew in front of your wife and children. A better plan would be to take a small unmaned yacht( no killing ) from a small harber and sail to the isle of man or a island off the coast of scottland grow your owen food and harvest the sea keep sheep for meat. That way you do not have to keep getting off the big boat putting yourself and family in danger to find more food. as citys like hull will be full of people looking for food.
You need to start by learning to research facts.
Average IQ in the UK is a bit over 100.
I don't what the IQ of a GP is, but I test in the high 120s and I don't think I'm doctor material. My wife tests around 140 (maths brain), but that doesn't make her a genius.
Getting back on subject, if TEOTWAWKI kicks in, I'm heading for the Humber with my family, on a boat. We'll take over one of the cargo ships in the humber. Set up farming on deck, rig out the boat to make it very difficult to board. Use the fuel oil for essential heating - with care, it should last years (those ships have 1-2000 Tonnes of fuel on board).