Being from the West Palm area, I have fished on most of the party boats mentioned. (I actually worked on 1 for 10 years) All are good, I personally have had great experiences on the boat in Lantana (Lady K) however the night trips can be hit or miss. I have had great trips on the Sea Mist (Boynton) and Blue Heron (Riviera and Jupiter) The Helen S and Fish City Pride (as mentioned before) are great too, but pretty far from WPB considerning the other options are much closer. (BTW Sea Mist & Lady K are South of WPB. Samana, Black Dog, Blue Heron are all in Jupiter North of WPB, a second Blue Heron Boat, as well as the Sea Horse are out of Riviera Beach (in between Jupiter and WPB)
Depending on your experience level fishing there (there is a definate learning curve to the bottom fishing (especially mutton snappers, etc) The smaller "open boats" (Black Dog, Samana, Sea Horse etc)(They all have websites) might be best as you would get more "hands on" help with only 6-10 customers instead of 30. But also about twice the price.
For catching pelagics (king mackeral, dolphin, etc. Your chances are similar on any of them. On the day trips, false albacore (they call them bonito) will be everywhere so at the very least you should have plenty of action.
I might suggest trying one of each (big boat/small boat) just to see the difference for future trips. If you did that I would suggest the small boat first (again for the learning curve).
Its very similar to fluking, blackfish etc, its no accident that a sharpies account for a big percentage of the best fish. But once you learn the diffences between the way they fish compared to up here, you will do very well.
Send me a PM if you need any more specific info (tackle, techniques etc)
This post edited by SebastianRed 11:23 PM 07/16/2008