April is getting towards the tail end of the season. Suggest that you shoot for February or early March.
I've done the Aggressor and the Peter Hughes. The Aggressor uses inflatable tenders. The Peter Hughes boat uses fiberglass boats. PH used to use the Wind Dancer, but the WD is now in Cocos. This year they brought the Sun Dancer from Belize to the Silver Banks to do the humpbacks.
As you probably know already, it is snorkeling only and not even freediving is allowed.
It is indeed a great experience - the in-water encounters, especially with the calves, are things that you will remember for life. However, it is not, in my opinion, a lot of bang for your hard-earned dollars.
The trip this year was over $3200 for a week for the boat only. And all that it gets you is about 4 1/2 days of in-water time.
You spend a looot of time riding on the surface waiting for the right moment to get into the water. Some encounters last seconds and some could last a few hours - it depends on how comfortable the Mother is with human intrusion and how well people behave.
If you shoot, I suggest that you come prepared to shoot with one wide angle rig for u/w and another, preferably a DSLR (no shutter lag) with a good size telephoto or zoom from the surface. If shooting from the surface, bring a towel to keep the camera dry and something like a microfiber cloth to wipe the lens because it will get wet often.
