I teach students that everything needs to be identified by feel so that if you are picking up a bottle in zero visibility you can be 100% sure that it is yours and it is the correct bottle for that depth. The bottle needs to be identified, not the regulator. If you know that the bottle is correct, you can trace the bottle to the first stage up the hose to the second stage in lights out or zero visibility. The team should visually verify that everything is copacetic at the earliest opportunity.
When I drop bottles, I always check the MOD sticker and contents analysis with the depth and check to make sure that each bottle placed by a team member is correct.
In addition, I teach students to mark their deco stops by checking specific features found in the cave or on an anchor line against their gauges. Like Rob, I usually try to make a secondary tie-off at 20 feet.
An exercise I do in a stage cave class is to have them stage up to Hill 400, drop the bottle and as we return to pick up the stages, I remove the student's mask and replace it with a blackout mask. He must identify the bottle by feel, pick it up, verify that it is his and the correct bottle and return to the stage. Once we exit onto the gold line, I'll return the mask and see if he remembers to flow check and verify the switch visually with the team at the next arrow. As we head down the gallery, I'll put him in the blackout mask and he'll have to locate his deco bottles by feel, verify that they are correct by feeling a feature in the cave (such as the Grim Reaper sign) and exit while estimating his deco stops by feel and by counting "Mississippi's". For example, if he dropped his Nitrox 50 bottle at the sign, he can verify bottle and depth by feel, make the switch and exit. If exiting the Eye, his first stop might be 50 feet where the flow pushes you into the first large rocks past the breakdown rubble. The 40 foot stop will be where the floor and ceiling get a bit tight. The 30 foot stop will be on the sand to the left where you emerge into the cavern zone. The 20 foot stop will be on the shelf over the manhole where he'll do his switch to oxygen. He'll again have to verify all by feel and estimate deco and any air breaks. 17 feet is the sand outside the cave and the student can approximate 15 or 10 feet and ascend to the surface once all estimated deco is completed.
While this scenario is unlikely in the Devil's system, it helps to teach awareness and provides a basic strategy to plan dives in which gas switches and deco stops might need to be made in poor or no visibility or with lights out. Being mindful of depth and features of deco stops and bottle drops helps raise awareness.
On normal dives, it's important to pay attention during gas switches. Don't just watch the procedure while on autopilot and automatically reply to an okay signal asking for verification if you are distracted. In survival situations it is important to be where you are and gas switching is a survival situation. Don't just watch. Really see what's going on. Pay attention. Pay attention throughout the dive. If for any reason you doubt with 100% certainty the correctness or safety of a switch - CHECK IT.
When I drop bottles, I always check the MOD sticker and contents analysis with the depth and check to make sure that each bottle placed by a team member is correct.
In addition, I teach students to mark their deco stops by checking specific features found in the cave or on an anchor line against their gauges. Like Rob, I usually try to make a secondary tie-off at 20 feet.
An exercise I do in a stage cave class is to have them stage up to Hill 400, drop the bottle and as we return to pick up the stages, I remove the student's mask and replace it with a blackout mask. He must identify the bottle by feel, pick it up, verify that it is his and the correct bottle and return to the stage. Once we exit onto the gold line, I'll return the mask and see if he remembers to flow check and verify the switch visually with the team at the next arrow. As we head down the gallery, I'll put him in the blackout mask and he'll have to locate his deco bottles by feel, verify that they are correct by feeling a feature in the cave (such as the Grim Reaper sign) and exit while estimating his deco stops by feel and by counting "Mississippi's". For example, if he dropped his Nitrox 50 bottle at the sign, he can verify bottle and depth by feel, make the switch and exit. If exiting the Eye, his first stop might be 50 feet where the flow pushes you into the first large rocks past the breakdown rubble. The 40 foot stop will be where the floor and ceiling get a bit tight. The 30 foot stop will be on the sand to the left where you emerge into the cavern zone. The 20 foot stop will be on the shelf over the manhole where he'll do his switch to oxygen. He'll again have to verify all by feel and estimate deco and any air breaks. 17 feet is the sand outside the cave and the student can approximate 15 or 10 feet and ascend to the surface once all estimated deco is completed.
While this scenario is unlikely in the Devil's system, it helps to teach awareness and provides a basic strategy to plan dives in which gas switches and deco stops might need to be made in poor or no visibility or with lights out. Being mindful of depth and features of deco stops and bottle drops helps raise awareness.
On normal dives, it's important to pay attention during gas switches. Don't just watch the procedure while on autopilot and automatically reply to an okay signal asking for verification if you are distracted. In survival situations it is important to be where you are and gas switching is a survival situation. Don't just watch. Really see what's going on. Pay attention. Pay attention throughout the dive. If for any reason you doubt with 100% certainty the correctness or safety of a switch - CHECK IT.
