Because there are a lot of ports with so much to do my suggestion is that you look at the ships tours, pick out the things that you would really like to do which might even be from two or three tours, cut out the inevitable ship shop stops and uninteresting bits then make a list. Go on the net and get a map and join up the sights then get a taxi and DIY. Some things are best done via the ships like snorkelling and sailing but most of the rest can be done, especially if there are four of you, in a more relaxed way without being herded and far more cheaply if you do it yourself. I strongly advise though that in Jamaica you only use cabs hired from within the confines of the port. Sorry I know nothing of the two parks you mention. As usual the secret is planning ..... Neil.
Many thanks for your advice Neil.
You can actually view and book tours directly online via princess website (www.princess.com). Also you will receive a very heavy book detailing all excursions and rough prices about 12 weeks before departure.I went to; Bonaire, Isla Margarita, Antigua and Curacao (among others) at Easter. Be careful with your choice of tour on Isla Margarita. Ours was a long and boring bus trip of about 3 hours (we got off once for 20 minutes). Dickinson Bay at Antigua is very popular, but go by taxi as it's cheaper. If you love sealife then snorkelling at Bonaire is highly recommended.
St. Lucia - Land and Sea Island Tour
Barbados - Catamaran and turtle swim
Grenada - River Tubing
Hope this helps.
Really appreciate your response. Thank you.