Is there any uk insurance companies that cover shark cage dives, zip lining, white water rafting
we usually advise our UK travel insurance company (UK Insurance) when we are doing anything different Last year we took a trip on a float plane into the wilderness in Canada but that was covered . My daughter uses the same company , she has had to pay extra for a snowmobile trip and and a dog sleigh adventure, they were classed as 'winter sports' . She used to hire sailing boats on holiday, so also paid a bit extra for that activity , no more than £15.
You would hope that the adventure companies you will be using would have full insurance cover but in some countries that is just not the case so you are wise in checking out your cover .
I just Googled 'UK Travel Insurance for Adventure Activities' and several items popped up.