Inch of gold is very popular on all the cruise lines. It has been on the ships for years. I have had a bracelet made and the bracelet has held up well. All the island have pretty much the same chain jewelry stores like Diamonds International, Columbian Emeralds, Tanzanite International. These are all good places to find nice jewelry. The ship will give their recommendations on other stores too. Do some price comparison before you leave home so you know if you are getting a good deal or not. They will barter.
I am the guilty party about saying "lead by the inch". It was a figaro bracelet I purchased on Carnival Fascination in 1998.
I wore it all the time while working in a restaurant. It only took a few months for the "Gold" to wear off. I kept my gaurantee and they did replace it on Tropicale the next year.
Same thing happened again. My original gaurantee had expired by then, and was not worth pursuing about it. I also had bought a neck chain that I wore less often and it still looked Gold in color, but looked like crap after the sheen wore off.
That being said, they may have increased the quality since then. One has to realize this is Gold plated jewelry not real solid Gold.
After wasting the money for the 2 pieces of fake Gold, I said no more. Instead of buying the fake. I bargained down a reputable Jeweler for a real Gold necklace. I am happy to say it is now worth nearly 3 times what I paid for it.
I also agree with Cruise Fanatic about them bargaining, and doing your homework. I want to add that the Ports you mentioned are not the best places to buy jewelry.
St.Thomas is the best place for gold, Mexico is the best place for silver.
If you just want the look without everyday wear and it being fake, it may be OK.
IslandCruz is right, St. Thomas is the best for gold. Out of the ports you mentioned, Grand Cayman would probably be the most reliable, but definitely not the least expensive. They do, however, have some decent stones (emeralds and sapphires) if you know how to tell a good one. Best wishes and have a wonderful cruise!!
I have not bought the gold by the inch, but have seen where you could purchase it for bracelet or necklace.
I will say, and I am surprised at it, I was on the Carnival Triumph this spring, and bought (they were selling several watches)a watch for $10. All of these were selling for that price, and to say the least, I have got my $10 out of it, and it is still working.