Possible Clues:

• Dive in
• Eventually commit oneself
• Fully commit to making a splash?
• The confirmed bachelor won't do something decisive
• Keep gauntlet husband's thrown and accept the challenge
• Finally decide to do a bungee jump?
• Bungee jumper has to get married
• Decide on bold action
• Say 57-Down
• Divers do this (3 words)