Question for instructors. I understand that agency standards can be quite generous in terms of student to instructor ratios but if you were teaching a class by yourself without using a DM or an Assistant Instructor, how many students would you be comfortable in managing at the same time?
1:1 team:instructor. 2:1 diver to instructor, maybe 3:1 in weird circumstances though I advise against 3-man teams for training.
That rule stays with qualified assistants. i.e. 1 assistant, then 2 total teams, 2 assistants, 3 teams, etc. This is OW only, pool is different.
You always play man:man coverage instead of zone coverage when in open water. If a team has to go up, you need to be able to manage both divers. You only have two hands, so you can only physically maintain contact with 2 divers if sh!t hits the fan. 3:1 is the rare exception, but never multiple teams.
I also disagree with teaching solo courses for OW, and Cave where they need to not only learn to dive as a buddy team with someone at their own level, but also learn how to overcome some of the bonehead things new buddies are prone to doing. Having the comfort factor of an instructor as a buddy is counterproductive IMO. I'll teach solo courses to certain people in certain circumstances, but if I have a choice, it's a buddy pair. Most other courses where you are learning new skills, I do actually think that teaching solo is better since you can direct attention of the instructor *intro to tech, CCR, DPV, etc*. Specialty type courses don't really benefit from that kind of attention, so getting to buddy pairs is more lucrative for the instructor and usually more fun for the students *AOW, Rescue, Trimix, etc.*.
I obviously don't teach for a shop....