SMB - Prefer a DSMB that you can shoot from depth. In case you lose the down or anchor line. Provides a visual and tactile reference that is quite useful in low vis. My preferred one is the 36 inch HOG one I sell with a 100 ft spool or small reel. I actually sell these (SMB and Spool) in a package with a line cutter, wet notes or wrist slate .
Slate - Slate is useful but I do prefer wet notes. I have two. One for teaching and recreational dives and one for tech dives. They have checklists, pages of deco schedules or words and phrases I use often. With heavy gloves on hand signals can get fuzzy.
Spare mask/snorkel -Mask, yes. Snorkel no. Rarely even take a snorkel unless I'm practically sure I'll use it or required to for teaching a class.
Spare Air/Pony - Spare air? No, it's a bailout for pilots. Marketed as ok for scuba but I won't allow them in any class. Pony bottle? Yes if you are trained to sling it properly and to use it. My own belief is if you are carrying one it's your back up gas so each diver should have their own.
Spare light - If I carry one light I carry two. Usually in our conditions three. Primary and two back ups. At least one back up. Back ups do not have to be expensive. I do carry a 160.00 Morph back up with me in addition to my can lights (either a 12 watt LED or 21 watt HID), but I also have a 45.00 one that is in my pocket as well.
Slate - Slate is useful but I do prefer wet notes. I have two. One for teaching and recreational dives and one for tech dives. They have checklists, pages of deco schedules or words and phrases I use often. With heavy gloves on hand signals can get fuzzy.
Spare mask/snorkel -Mask, yes. Snorkel no. Rarely even take a snorkel unless I'm practically sure I'll use it or required to for teaching a class.
Spare Air/Pony - Spare air? No, it's a bailout for pilots. Marketed as ok for scuba but I won't allow them in any class. Pony bottle? Yes if you are trained to sling it properly and to use it. My own belief is if you are carrying one it's your back up gas so each diver should have their own.
Spare light - If I carry one light I carry two. Usually in our conditions three. Primary and two back ups. At least one back up. Back ups do not have to be expensive. I do carry a 160.00 Morph back up with me in addition to my can lights (either a 12 watt LED or 21 watt HID), but I also have a 45.00 one that is in my pocket as well.