Ten years ago, I took my first cruise and found a different message board similar to this and looked for as many tips as I could find. One tip that I took away was to take a small box of Cheerios from the breakfast buffet to take with us when we went snorkeling in Cozumel.
I got all situated with my fins, snorkel, mask, life vest and Cheerios and headed out into the water. I really have very little experience with snorkeling but was enjoying all of the fish that I was seeing. I decided it was time to feed the fish. Hmmm, how am I going to open this bag of cereal? I'm floating in the water and have nothing sharp and only wet fingers. I worked and worked and finally ripped the bag open, only to have the cereal all go flying in the water around me. Instantly it was a feeding frenzy and there were fish all around me, touching me and gobbling up the cereal. I freaked out - and quickly got away from all of the fish that were surrounding me.
Needless to say, my friend's container of Cheerios went back on board with us. Unopened. 😊