[Sailor Steve]

I don't think so. If you're on land you can feel an explosion before you hear it, because sound travels faster through the ground than it does the air. Likewise water vs air.

Underwater the shockwave is just extreme sound, and the click and explosion should travel at the same speed. The softer sound will dissapate faster, so the click will not be heard at any great distance. I think if you don't hear the click you know you are in no danger. If you hear the click then the thing is reeeeeaaal close!