Everyday this forum slips further from God.
Here's a tip for you..ask the insurance company, anyone else you ask, will just provide conjecture.
Don't get insurance with Alexander Swan they are total rubbish...
You'll also have to ask if they'll cover the scuba equipment...
About three years ago I had an ' open driving policy ' with Aviva, my vans were insured for any driver, no restrictions, it may be worth asking them if they still provide this cover.
I've just changed 4 vehicles to any driver from named drivers and it was cheaper so I had a refund on my policies! With Alexander Swan and no problems with them.