I use RSA too, for the same reason you mention, and they have a good off-road coverage.
It states in the attached booklet:
6. Off Road Assistance: We will recover the Insured Vehicle from off road areas including sandy areas, desert and/or basement parking’s within the UAE. However, recovery in the desert applies to Insured Vehicles that have four wheel drive capability only, excluding competitive events or carrying passengers as part of business. This service is limited to three times in a year.
Off road cover: The coverage under the Policy is extended to include loss or damage to Your Insured Vehicle and/or Third Party Liability, whilst being driven off road. Provided that: (a) Your Vehicle has four wheel drive capability (b) It is a private vehicle only In the event of a claim the Police Report should be provided.
What we don't cover: If You are participating in any kind of dune-bashing, competitive event or race. If You are carrying passengers in the Insured Vehicle, for hire or reward.