Sometimes a simple google search will help you out. That's how I found one local dive team, however they are slowly getting out of s&r because of liability issues and funding (it's a private group, not attached to an FD or PD). My husband tripped across an offer because of the dive flag on the back of my car. He was pulling into a fire station to pick up an application and the conversation went something like this as he was getting out of the car:
FF: "You a diver?" (nodding to the sticker on the back window)
DH: "Yeah..."
FF: "We're hiring divers."
DH: "Well, my wife's more into than I am."
FF: "Take an application to her, we could use some more divers."
This was about a week ago, haven't heard back from them yet .. am going to one of their meetings next week, DH talked to the chief two days ago and he said that's the fastest way to get hired on, since half of their volunteers don't show up to meetings like they're supposed to. We were told OW is the only requirement, they prefer AOW and stress & rescue but will help you get whatever training is necessary, including all the Firefighter certs since their dive team are PPC FFs who's main job is diving but also go on fire calls if needed.
