In So Cal, DM's stay on the boat. You dive the site with just you and your buddy.
Because in 10 to 20 foot vis in a kelp forest, no DM could track 2 teams let alone 10 teams while in the water. From the boat you can track the bubbles, so you know where the breathing teams are (with the exception of the closed circuit rebreather divers).WHY is that, anyway?
The rule in the Monterey area is: "if you don't surface, we can't save you." However, when the crew sees a problem at the surface, the boat crew can react very quickly.
Unless of course, you want me to throw up on your back.9) Do not stall in the entry or on the ladder- if you have a problem let the crew know and move out of the way, there are others trying to get in the water or on the boat.