Posted January 10th, 2018, 03:09 AM
I've never had a problem. I use the ziploc baggies and only put about an inch deep at most. I leave them sealed for a few months after we get home. After Christmas one year, I bought off clearance the clear ornaments at craft stores, and put sand and tiny shells inside (they are all over the beach by the water taxi in St. Marten, btw), then the year and place, I write on the outside.
The past few years I've brought back rocks and made a rock garden. Never had a problem then either. I did see on one cruise, security made a kid throw his conch shell back in the water.
Holland Eurodam--Eastern Caribbean--Nov 2017
Carnival Splendor--Southern Caribbean--April 2017
Norwegian Gem---Southern Caribbean--Nov 2016
Royal Caribbean Navigator of the Seas---Eastern Caribbean---April 2016
Royal Caribbean Adventure of the Seas--Southern Caribbean---April 2015
Royal Caribbean Brilliance of the Seas---Canada and New England---October 2014
Carnival Valor---Southern Caribbean---April 2014
Holland Oosterdam---Alaska---Sept 2013
Norwegian Star--Western Caribbean---April 2013
Holland Rotterdam----Alaska---Sept 2010