In reply to ClimberEd:
I've used Voyager for travel insurance, including off-piste without a guide - seems pretty reasonable via my broker.
Used to have my contents insurance with Norwich Union/Aviva, because they covered my kayak (and bikes, I think) for damage while in use, not just for theft. Had to change policy due to other items I now need to cover, though - can't remember the details of current policy, but could check for you.