I was shot in a town, and left for dead with my legs broken. I wanted to respawn, but know I have to die or become unconscious for that. I was close to the ocean, so I crawled to it and submerged myself. After a minute or two under water I received the "You are dead" message, but when I press Escape, the "Respawn" button is greyed out.

I can open my inventory and see that it says I'm Hungry, and I can toss/pickup my backpack, but I cannot respawn.

I've logged out of the server and logged back in, but it was the same, I would spawn alive for a minute or two, then I would drown and be in the same scenario.