AFAIK, the RC 30 did not have its mast stuck in the mud:

We saw it on the way into the harbor, not long after it flipped.

Here's a photo taken less than an hour later of the righting operations:


BTW, they were not the only boat to capsize in the harbor. A NACRA F18 capsized jibing around the statue - we passed them to take the F18 lead in the race.

The critical issue is not the size of the catamaran, it's the ability to self rescue in a short period of time.

Also, New York harbor is not "unsafe" for catamarans. It's a busy place. The currents are tricky. The wind is weird. You've got to keep your head out of the boat and pay attention to what's going on around you. Other than a close call with an anchored barge (I swear the thing was like a magnet), we had no problems navigating the harbor.