Small Boat Rental - Self Drive - Snorkeling - Anyone done this before??

I am trying to figure out what to do on our stop in St. Maarten. I stumbled across a few of these small boat rentals (for the lagoon?), but have not found any reviews on the boards here.

We are an active couple looking for something fun! We would love to snorkel, but do not want to pay for a snorkeling tour with a bunch of other people, as we have all our own gear and love exploring on our own!

Any advice on either topic is appreciated!

We did this several years ago and really enjoyed it. Is there a company up and running renting these now?