Yep,
Just hop the ferry over to Saba and enjoy some of the very best diving in the Carib. In fact, were it I, I would skip diving St. Maarten altogether and just do Saba.
However, the scenary (pulcritudinous type) on the beaches of St. Maarten is hard to beat. This is especially true of the French side of the island. Since this is a family channel, I will not write any more, but you get the idea!
Back to Saba: you can arrange for diving with Sea Saba or Saba Deep whilst on St. Maarten. Or you can take a chance and go over without reservations. Usually, there is room on one of the boats, but you will be taking a some risk.
By the way, if you go with Saba Deep, they normally come back in between dives and you can do your SI whilst sipping a virgin pina colada in the dockside restaurant/bar, a wonderful way to get rid of nitrogen! One more thing about Saba Deep: Big Mike the dm is a legendary character. He can be gruff on the outside, but is a masterful guide and will get you to the very best sites!
Scorpionfish