I have read a lot of Navy history about WW II but have never heard a description of what should have resulted in a significant number of casualties. The shock of a shell exploding or just impacting armor would be largely undiminished for quite a distance. If you were standing against the wrong bulkhead, on the wrong deck, or in the wrong passageway, you could be ripped open or parts of you turned into jelly.
Fire. Shrapnel. Smoke. Blast.
The blast effects of explosions of naval shell sometimes left men dead without a single mark on them. Just turned to jelly inside.
Entire gun turret crews of men killed by smoke.
Just awful reading.
In that same book “Neptune’s Inferno” there was a particularly interesting account of a destroyer that picked up a group of Marines led by Chesty Puller that had been caught behind enemy lines.
The Marines were fed and catered to by the crew for a day and a night, and when it came time to go, the Captain of the destroyer asked if they wanted to stay longer, and Puller said no...they would rather be on land. When the puzzled captain asked him why, Puller said something like “On land, you know where you are. You can fight back. You can burrow into the earth or get shelter. Out here on the ocean...” (I don’t remember the exact words, but the sentiment was apparent to me)
In the Battle of Savo Island, we had nearly a thousand men killed in a matter of minutes, overall, the shooting lasted long minutes, and the time from the first shot being fired to the Japanese withdrawal was about 45 min, IIRC.
It was brutal, savage fighting with Fire, Shrapnel, Smoke, and Blast effects, and in some cases that nobody wanted to talk about, in the end...sharks.
Makes me shudder to think of it.