A year or two ago I asked if anybody had any info. on this topic. Nobody did but I recently fornd this reference. If interested take a look:
http://www.dlsports.com/underwater_h..._shooting.html
In this test both glocks and 1911s were tested with .45 and the Glock with .40. Nothing blew up and the 1911s worked well with ball ammo. The range was very restricted, I guess you have to shoot sea monsters at contact distance. Now who wants to try a Luger? Just kidding of course.