Gilligan
Contributor
The one time I did not have my SMB and reel was the only time I've actually needed it.
Coconut point, Apo Island - getting caught in a down current and separated from the guide and my buddy. Never dived without it since. While it's nice to have, many divers don't use one
Like chip104, all it takes is one time to make you never dive without one again. I never do.
For me, Palau, late 1980's, still a very inexperienced diver. Surfaced about a half mile from the boat, divers scattered all over, strong winds, choppy seas, no SMB. Whistle + wind = useless. Experienced dive buddy with SMB = boat pickup. Case closed.
I also carry a small signal mirror. It's red on one side and regular on the other.