Hunt in the rain. BUT should you somehow screw up, and gut shoot a deer, DO NOT follow it. A gut shot deer, if not pushed will usually bed several times, and expire within 200 yds of the shot - within 6-10 hours. Even with no blood at all you are better off not following it, and taking your chances. A gut shot deer can go for miles if pushed, its septic shock that kills it, not blood loss.
I definitely do not condone bad shot selection, but should it happen -please follow this advice.