How can you learn to hold your breath longer?

Question

Im joining the U.S. Coast Guard soon and will eventually go to A school to become a Rescue Swimmer. i really would like to know how to hold my breath longer, and how to train to hold it as long as possible. any exercizes or techniques that can help with this?

Answer 1

be careful, you can damage your lungs

Answer 2

Although not very wise, minimal hyperventalation can help increase your breath.

Just try deep breathing before you get in water