Charter companies have differing policies for required experience. At some places if your credit card clears, you're qualified. At others, your resume will be scrutinized, and if there is any question about the level of experience, a
captain will be required for at least one day. More days may be required if there is a need.
Certificates are just part of the puzzle. Time on the water. Experience
anchoring, maneuvering a similar sized vessel (under power and sail), picking up
mooring balls etc. all play a factor.
If you've never sailed in this area a Capt for a day or two is not a bad idea to get you comfortable with the vessel and the area. Most charter companies will charge only $150-$200 for a Capt per day.
Feel free to send me a PM if you need any further info.
Enjoy your trip if you make it down this way.