sorry to rain on the parade, but leave the rods and bring snokels and fins.
about 7-8 years back, my wife and i spent 3 weeks on st lucia.
there are NO fishing opportunities i could find. the fishing on st lucia is typical of what you find in all of the southern caribbean islands. TOTALLY FISHED OUT!
the locals have all but vacumed the waters clean of almost everything that swims.
also typical of islands in the area is the way they were formed. they are all volcanic in nature, so they literally rose from the sea. there are no flats or even many shallow areas where one can wade.
a word of caution. be careful on st lucia. high crime rate, and big time drug problem. both made worse by the extreme poverty in the cities.
don't go out at night, esp into castries or soufrierre unless accompanied by a "local" guide, or someone who talks the lingo down there. esp be careful of the friday night "jump up" festival in gros isle. locals feed the tourists spiked drinks, and the tourists wake up hours later to find themselves seperated from all their valuables and their $$$. don't go here unless accompanied by a local person who will look out for you.
attacks on tourists are all too common there, but are always hushed up by the ministry of tourism. if i were not 6'2", 250 pounds we would have been in some BIG TROUBLE one night. some locals "insisted" i buy the local ganja. when i declined, things got heated.
however, st lucia is a beautiful island, blessed with an abundant tropical rainforest.
feel free to email me if you'd like more detals.