Can you safely tow a watercraft/jetski with a compact car?

Looking at picking up a waverunner from yamaha in the future. I asked the dealership and they said they've seen geo metros towing jetskis to the lake and that it could be done, especially with a single watercraft.

Then I went to the car dealership where I bought my car and asked the service techs and one said he's seen a lady with my car and a small tow hitch on hers.

The other guy (seemed like the manager) got kind of upset though and mentioned how my car wasn't built for it and was only designed for A to B driving...

I'm thinking about the warranty here, because if it can be done and is done often... I'd just keep my car. I don't have the cash to buy a truck/suv and my commute needs a car that gets good gas mileage anyway (almost 95 miles round trip 5x/week).

Any of you guys tow small things like watercraft/atvs/etc with compact cars?

He mentioned the transmission and axles weren't built for it and while I agree.. it seems that ~140hp should be just fine for pulling a small item, especially with a 5spd where you could manage the rpms and gearing...

It's about 50 miles from my place to the lake..

I'd probably be towing it up there 3-4 times a month MAX. I'm worried about voiding my warranty. I got the idea that the asshole service advisor was just in a bad mood (looked pissed before I even said anything or introduced myself).