U20 owner Mike Josselyn towed his U20 from San Francisco to Park City, UT with his Subaru without any problems. The specs say the U20 weighs 1,260lbs. Add in the trailer and other camping/sailing gear that may not be included in the spec and maybe the total weight is 2,000lbs. I think a Subaru is good for 2,700lbs.
Edit: I viewed a Subaru spec page and the tow limit is 2,700lbs with trailer brakes. Hard towing (hot, uphill, no trans cooler) 1,500lbs. Regular towing without trailer brakes: 1,000lbs. Seems that brakes are the biggest weakness and if your trailer doesn't have brakes and you were planning on traveling over mountains, it could be a problem. If you are traveling on relatively flat terrain and only a few small trips, then I don't think it would be a problem without trailer brakes. Just know that your stopping time will need to increase and the brakes might get soft.