Well this is an easy one!!!!
I, like most men who swim in warm waters, end the dive and upon exiting the water, have swimmer's wood. That's why I always carry in my dive bag an, "Inflata-Ho" system for whenever the urge arises. She/it is multifunctunal and has saved me many times. How you ask??? Because she/it doubles as a life saving raft in emergency situations.
Inflata-Ho has saved me many times when I deemed the moment, "To be an emergency"!
Jim