A couple jetskis shouldn't be any problem. Back when I was in college I used to tow a 2 place snowmobile trailer with my Subaru Loyale 4x4 wagon to southern VT. I suspect my 1/4 miles times would have been in the 45 second range
My concern with tow vehicles is always getting traction on launching ramps. I used to have a beat up 17' Whaler that I towed around with my 2WD F-150. We belong to a club that owns a house on the Pawcatuck River with a "launching ramp", putting it in is never a problem. Getting it out was another story. One wheel drive doesn't cut it and even if I had a locker it wouldn't have been any better. I ended up having to drive just over the crest of the "ramp" and fortunately I had the anchor line which I tied to the trailer tongue and was able to get it out. 2WD is fine for towing a camper or utility trailer, but I want 4WD for towing a boat trailer because a lot of ramps suck.