I brought a lg and sm Sebenza there with me last May (in checked luggage), and had no problems when carrying either of them clipped in a pocket around the resort (Ocean Club West) or out and about. Entering the country, we just waited in line to have our passports stamped and no one inspected our bags; my bag was searched upon departure, but it was in my presence and I'm sure they wouldn't have confiscated my knives had they seen them.
Considering what a diving/snorkeling mecca the TCI are, I imagine that knives are pretty common.