Cayo Costa State Park is on the entrance to Charlotte Harbor.

Sea conditions from Big Carlos Pass to Cayo and Boca Grande appear and I have not yakked to Cayo, always calm for example

http://forecast.weather.gov/MapClick.php?lat=26.707586641427362&lon=-82.26699829101562

an excellent novice camping trip: Pine Island to Cayo SP then down the coast south and back to Pine.

No tsunami.

Seas outside Sanibel and Captiva normally calm.