Blood underwater looks green. I learned this when the divemaster speared a lionfish and cut off its poisonous fins. I then started screaming/squealing when I saw this greenish color coming off of my arm later in the dive.
I had been swimming along, minding my own business, checking out coral and sponges and tropical fish. I'd even seen a couple of sea turtles (my favorite). A pretty good dive so far in the beautiful warm waters off of Roatan. As I looked into the tube of a sponge, suddenly there was a sharp pain in my left forearm. I looked, panicked, to my left and saw a huge green moray eel backing into the reef. I screamed and hyperventilated, then held pressure until we got to the surface at the end of the dive.
Fortunately, one of my dive buddies was Michelle, a friend from residency and fellow family doctor. She washed out the biggest wound and put on steri strips. We then did what any self-respecting doctors would do and searched the Internet for treatment recommendations. I found an article from 1992 where some emergency medicine folks had cultured the mouths of moray eels and found Vibrio and Pseudomonas most commonly growing. Off to the nearby pharmacy where we asked for ciprofloxacin (no prescription needed- this is Honduras, after all).
5 days later, no signs of infection, despite testing it in both pool water and ocean water a few times :) Isn't the body amazing?!