........boat towing company do you generally use?

Do you sign an annual contract with them and, if so, for what towing
coverage/tow?

I have always used BoatUS as there is always a vessel covering the areas we
boat. In the past we opted for max coverage due to the amount of time we
spent in open water.

With our 21 footer we opted for the basic coverage (especially since the
membership brought us some discounts at BoatUS and West Marine stores) as we
do not plan much off shore boating with this boat. ;-)