Most Jet Ski Trailers weigh around 200 to 300 lbs and then the Jet Ski could weigh around 1,000 lbs.
So to tow a Jet Ski you need a Towing Capacity of around 1,300 lbs to 2,000 lbs depending on the weight of the Jet Ski Trailer and the Jet Ski itself.
Some small cars can safely and easily tow a Jet Ski and Jet Ski Trailer so it doesn't take much of a vehicle to tow a Jet Ski.