Capt Jim Wyatt
Hanging at the 10 Foot Stop
Staff member
ScubaBoard Business Sponsor
Scuba Instructor
On another thread there is the start of a discussion regarding the fact that cave divers cannot agree on how to mark jumps and T's. I teach a procedure that I'd like you to consider and will try to explain it.
Jumps:
Whenever we jump from one line to another very often we begin the jump at a set of double arrows pointing toward the nearest exit and these arrows indicate the position of another line. I teach every teammate to place a cookie, or some type non directional marker on the exit side of the arrows. The jump line is then laid down. So...if there are three team members there are five markers on the line, all serving as visual cues. Two arrows and three non-directional markers.
When the team comes back to that line a navigational decision must me made as to exit direction. At that point there are five visual cues as to which way the exit is. The person running the jump line waits at the reel and waits to see if the other two team members cross and wait on the exit side. Those two team members pull their non directional markers off of the line. Once the person pulling that reel is satisfied that the other two are in fact on the exit side then, and only then does that diver even touch and pull the reel and then removes their non directional marker. If team mates wait on the wrong side of the line/markers, not the exit side they do not pull the reel until after they signal the divers to move to the exit side and verifies that they do so.
If during the dive after that jump is installed the team members get separated and when they get back to the jump line the team will see that the separated diver has removed their non directional marker they will have a high degree of confidence that the separated team member has started down that exit line. If that marker remains in place then a logical assumption is that the diver is behind them. The team can then act accordingly.
Of course this protocol must be discussed topside and everyone must fully understand and agree to the procedure.
T's:
Same procedure even though generally no double arrows are present, sometimes no arrows are present. Once the team gets back to the tee where a navigational decision must be made there are ample visual cues as to exit direction and the same if team mates get separated beyond the T we can know with a high degree of confidence if our buddy is ahead or behind us based on the presence or absence of their marker.
Jumps:
Whenever we jump from one line to another very often we begin the jump at a set of double arrows pointing toward the nearest exit and these arrows indicate the position of another line. I teach every teammate to place a cookie, or some type non directional marker on the exit side of the arrows. The jump line is then laid down. So...if there are three team members there are five markers on the line, all serving as visual cues. Two arrows and three non-directional markers.
When the team comes back to that line a navigational decision must me made as to exit direction. At that point there are five visual cues as to which way the exit is. The person running the jump line waits at the reel and waits to see if the other two team members cross and wait on the exit side. Those two team members pull their non directional markers off of the line. Once the person pulling that reel is satisfied that the other two are in fact on the exit side then, and only then does that diver even touch and pull the reel and then removes their non directional marker. If team mates wait on the wrong side of the line/markers, not the exit side they do not pull the reel until after they signal the divers to move to the exit side and verifies that they do so.
If during the dive after that jump is installed the team members get separated and when they get back to the jump line the team will see that the separated diver has removed their non directional marker they will have a high degree of confidence that the separated team member has started down that exit line. If that marker remains in place then a logical assumption is that the diver is behind them. The team can then act accordingly.
Of course this protocol must be discussed topside and everyone must fully understand and agree to the procedure.
T's:
Same procedure even though generally no double arrows are present, sometimes no arrows are present. Once the team gets back to the tee where a navigational decision must be made there are ample visual cues as to exit direction and the same if team mates get separated beyond the T we can know with a high degree of confidence if our buddy is ahead or behind us based on the presence or absence of their marker.