When I taught DP dives were to 50, 100, 100, 110, 115, and 125. The deepest part of the quarry was 130 and water temps were 38 - 40 at the bottom. No need to go to 150 anyway. Set the dives up for proper run times and decompression. Decompression Procedures courses often get too hung up on depth. The objective is to have the skills and build up to max depth over time.
Jim,
As far as I'm aware, all AN/DP courses here end on a ~150-ish foot wreck. That's why we train, that's the destination. You can do 130ft wrecks every day here, but can't go beyond without tech certs. There's always a location bias to training and why people should take the appropriate courses for where they ultimately want to dive.
These kinds of depths are much different up north than they are here, I assume. We aren't dealing with "freezing temps" and near zero vis conditions. It's very possible 150ft where you train is a whole different skill with potentially nothing to see. I don't know... I've only dived in the Caribbean and Bermuda prior to being certified and Florida after being certified.
Speaking of differences... went to the Hydro yesterday. I'm sure @Marie13 will appreciate the temps at 165ft....