If you are using a someone else to tow your caravan, don't assume their insurance will cover damage to your caravan whilst in transit. Check the T&C's of their towing service to find out and if necessary ask. It's unfortunately quite common for services like this to not cover the the trailer or its content and they expect the customer to have their own insurance against loos or damage. It much the same as car parks and caravan storage sites where they expressly exclude loss or damages to customer property.