k: That's the High season in general but there are a couple of weeks that are historically one price level down ie; just after new years when the holiday crowds go home.
Sunsail (and others) would include a paper Price chart along with their brochure where you could see the shifts throughout the year......You might be able to get an on-line version - But if you call, just ask them where the variations are during your time frame, again three weeks is a good bargaining chip - just stop by the base every so often to get free water & fresh linens
If You want to talk to an excellent Sunsail Rep
Sunsail Vacation Planning - USA
Toll Free: (800) 327-2276
Have a great time