Depends on the boat you are on. If there is a swim platform, I like to step over the transom onto the swim platform and hang onto the transom while doing my business. On a center console, I like to hang over the gunnel while holding on the center console with a mooring rope.
Sunday, I didn't have time to prepare. I coughed and the next thing I know is my pants were full. Rather embarrassing as those were the only pants I had for the trip. We got the boat moving and I held them over the gunnel for a thorough saltwater wash down. This procedure was repeated twice that day.
I just hope and pray that a certain person that I was fishing with doesn't post pictures of me in this predicament. If he does, I will post a few of him doing some things that could prove to be very embarrassing.