Long ago I did Marine Patrol work. My issued sidearm was the S & W Model 66 in .357magnum. I treated it badly, wore it while in the water, and was a sloven about regular lubrication.....with all that, it functioned flawlessly, even right out of the water. I would buy one again, just because it held up well.
For the last 10 yrs, I have been the proud owner of an HK USP in .45. It is sometimes stored on my boat, and has also joined me in the water on a couple of occasions. I am more diligent about cleaning it ALL my firearms now, and the USP has never let me down. It's "Hostile Environment" finish was developed for the HK Mk23 SOCOM pistol and has been proved to hold up well even in salt water.
I also keep a Mossberg 590 Special Purpose Mariner 12ga pump gun (the one with the line launching setup) on my boat. It sits alot, and sees minimal care. I test fire it/practice with it every month, and it runs smooth, even after 8 yrs on the boat.
I would stand behind any of these choices.