my 18' is on a single. singles suck. bouncy, and they whip back and forth. tandems are the way to go.
i have a single towing a 18 ft eliminator jet. no swaying or excessive bouncing for me. Dual just looks cooler though. but now that i have read this thread I'm afraid of what can happen in a blow out
triple axle for an 18'... just cause you can. heh.
^^^ has never backed a short triple axle with a crewcab. Single works fine for my 19', but have tandem on the 21' cruiser (2800lb)
i cant even imagine turning with a triple axle trailer... let alone doing anything else with one.