USAA typically doesn't ensure aircraft, yachts, motor coaches, and motorcycles. The first time I was pawned off to another well-know company as a USAA "preferred" customer, I ended up with a $3500. annual RV insurance premium. I quickly figured it out, cancelled the policy, and landed a great policy with another company for $1650. Recently, I was pawned off again for a new motorcycle. Flo quoted me $385./yr. I looked elsewhere and immediately found more coverage for $255./yr (30% less!!!). So my friends, the days of trusting USAA to take care of us are long gone. Think carefully before you get in a canoe with "Flo".
Regarding the above comment,. In the case of aircraft insurance, USAA does have a partner company. They offer USAA members an additional discount in addition to a AOPA discount. Can't comment on the other coverages.