+1.

I called the park office at amistad and discussed the law with the ranger folk there, they didn't have a problem with me carrying a long gun or a pistol on the boat, ref the castle law as it applies to boats, but if for some reason your boat was to be searched you would want to make sure the person searching your boat knew what he was about to stumble across. There was some confusion at first what the law meant so it would probably be best to call and talk to a lake official yourself before you go. I carried my AR-15 with a 30 round mag and a spare mag and I also carried my glock model 23 .40 cal. I had peace of mind, stayed on the U.S. side of the lake, and caught lots of toads....

DO NOT GET CAUGHT WITH A GUN OR EVEN A SHELL in Mexico.
I remember a case years ago when local man crossed the border in his pick up truck and was stopped and searched. A single .22 round was found in his glove box (which he claimed was left over from a target shooting trip or something like that). Hem was jailed and remained there for a few months until a Texas State Senator or Representative was able to get him released.

You need to understand that it is ok for them to cross the border and shoot US citizens, Border Patrolmen, and LEOs, but it is not ok to do the same to them.

Why even go to where you have to carry a weapon to feel safe fishing? My god, with all the first quality lakes in Texas I would not set foot on dangerous border waters.

Amistad and Falcon are super dangerous places. Mexicans everywhere. Its just horrible. We need Davey Crockett back.....Damn the Mexicans killed him.

I would carry a minigun and some grenades. You also might want a short barreled shotgun and maybe some ninja throwing stars. A belt fed 1919 wouldn't be a bad idea, if you could pod mount it on the back deck.