Why would you carry a sidearm when fishing?
We have some reasons.
Please Read Disclaimer First: Dispatching large oceanic fish, especially potentially dangerous fish, with a bullet is common. Fish are speared, shot with bow and arrow and power heads (bang sticks). State laws vary. Federal law allows firearms.
Fishing in the ocean, especially in the Gulf of Mexico, is not what it once was. Now people catch big sharks, take a few pictures and video, then cut the leader to let the apex predator swim free.
Back in the 70s, 80s and earlier, big sharks were brought alongside the boat and often shot. No more.
However, the ocean is still full of big fish that you can bring on the boat. Some of these fish are big enough to break rods and injure people in the boat if they are boated "green."
Green means the fish still has plenty of fight. Put a 100-pound "green" cobia in the boat and you will quickly learn the damage one of these fish can inflict.
A good handgun will dispatch a big cobia, stingray, amberjack, huge mackerel, any of the billfish or even a shark if you really want to kill it. Yes, people eat stingrays.
Why do you want to end the fight in a hurry? In the video linked at the top, the Ben and Shag Baker were fishing in the Gulf of Mexico out of Keaton Beach when a Southern summer thunderstorm suddenly popped up. They fished with Capt. Pat McGriff with One More Cast guide service.
While they did not have a whopper on the line when the squall line appeared, they did have to get back to the dock before it hit. They did not have time to fight a cobia for 45 minutes. That S&W .357 Ben wore in a Tucker Gunleather chest rig was just the thing to tame a cobia or big stingray.
Bull sharks in places like Lake Nicaragua being an exception, you don't generally need a gun to dispatch a freshwater catch.
If you chase giant blue and flathead catfish, you might appreciate a handgun when you pull a 100-pounder to the boat.
You can use the gun to dispatch fish you'd rather not bring in the boat but do not want to release alive. In the Southern states, the snakehead is a exotic fish that needs to be removed from the ecosystem. A load of birdshot from a Judge takes care of the water varmint.
It is not common, but people are robbed while fishing. YouTube has plenty of stories of people being shot at while fishing.
You need to protect yourself. A hip carry can get in the way, as demonstrated in the video. A pocket carry is going to be next to impossible to draw while sitting in a boat seat.