Marymac90 writes:

"This song actually
admits and talks seriously about how we are sending troops
into harms way, and they might not all come back."

I have never connected this hymn with sending troops into harms way, though I suppose it could read that way. I have always seen it as being about the perils of the sea, not the perils of being in the navy., All(OK, most) sailors use and venerate this hymn, fishermen, lifeboatmen whatever.YOu fefinitely don't need a naval uniform.    There is a tiny reference at the end that includes hostilities as one of the dangers of the sea, but that is all:
"From rock and tempest fire and foe
Protect them wheresoe'r they go".
But perhaps the author was a naval man, and was thinking more of war than I was?