APRIL 2008 UPDATE: FATHOMS IS NO LONGER IN BUSINESS
We just had lunch at Fathoms which is in the Lagoon on the Dutch side of St. Maarten between Bobby's Boatyard and Turtle Pier. They have a dinghy dock but be careful because it is very shallow. They have a stage so they probably have entertainment some nights.
About 6 weeks ago, we were having problems with our WiFi provider and we really needed to send out some important email so we went to check out the bar/restaurant Fathoms. Their WiFi service was OK and free. We had lunch there and it was OK, but... I had the tuna steak sandwich but didn't see the advertised avocado and it was kinda ho-hum. Bob had the lunch special. Cokes are $2.00 and come in a glass. Normally you get a glass of ice and the Coke can. Lunch specials might be $8.00. Lunch seems to be between $9-$12. As you can tell, I'm not wowed by the place and we don't plan to go back. I'd rather go to MacDonalds when I need free WiFi or Rik's Place. I would have preferred the taco salad at Rik's place than Fathom's fish & chips. Rik's Place has a dinghy dock. Rik's is in the Lagoon between the Dutch bridge and Palapa Marina (across the street from MacDonald's).
Today we took our laundry over to Bobby's Boatyard and we went to Fathoms again for lunch to give them a second chance. We both had the fish (mahi-mahi) and chips for $10 each. It came with a bit of salad and fries. Three small lumps of fried deep-fried fish that were 2 or 3-inches long.
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Jimbo's at Simpson Bay Marina has/had free WiFi. Haven't been there in a while though. One reason is because it takes so so so long to get your check to leave. I think we still have quite a few "Jimbo Dollars" that we must use or give to someone for free drinks.
So, remember that this is just my opinion... might be different for you :)
All the best!