sonofzell
Registered
Greetings!
I'm a relatively new diver - I've been certified for 4 years, but sadly my schedule and budget do not allow me to get out nearly as much as I'd like! I was able to squeeze in a beach dive this past weekend. It was the first time ocean diving from shore for both my daughter & I.
While the dive itself was relatively uneventful, I recognized some poor judgement on my part that raised some questions regarding navigation. Fortunately, the consequences ion this case were minor, but the need for improvement seems pretty obvious to me...
#1: Measuring and tracking distances underwater.
During this dive, we were advised of the locations of several reefs using visual points of reference both on and below the surface. We aligned with a particular buoy, surface swam until we were parallel with the end of a rock jetty, and submerged. At depth, we proceeded due east for approx. 50yds and found the first reef, exactly where we were told it would be. The remaining waypoints were simply approximated distances ("when you get to another sand bottom, swim another 25yds, you'll hit the next reef", etc.). In this case, the reference points were pretty idiot-proof, but my question is: Hypothetically... If we went off-course and "missed" our landmark(s), how would we confidently know HOW far we'd swam? Using only my estimations, the directions we'd been given were pretty spot-on, but I can easily see how simply "using my judgement" could lead to a dangerous situation, especially in a poor-visibility environment. We were diligent about using our compasses to ensure we would be able to accurately return on the same course, but as for specific distances, I feel like there's surely a better method than basically estimating how far we'd travelled between points A and B. I do carry a finger reel, but it is relatively limited in length (60', I believe). This particular dive being in Florida, I was also using this line to tow our SMB. I've done guided wreck dives in which our DM had used lengthy lines as guides, but truthfully never considered (perhaps naively) one of those large-capacity line reels to be "standard" gear. Using a similar line reel, I can see how distances could be easily measured; I guess what I'm asking is what, if any, alternate methods should I be prepared with to more accurately determine underwater distances?
#2: Current considerations for dive planning.
Here's where I really "dropped the ball" in terms of planning on this dive: given our shallow depth, we knew this was a no-deco outing, and mutually decided on both "turnaround" and "surface" thresholds based on air supply. Applying the "rule of thirds" and actively communicating, we executed the dive exactly as planned. Thus, you can imagine my frustration when we surfaced, only to discover that we were easily 100yds asea from our original point of descent! About 10 seconds after deciding to snorkel ashore, the reason for our miscalculation became painfully apparent: I had failed to account for the strong rip current when applying our return to shore! Even after moving longitudinally to dodge the rip zone, we ultimately spent over 30 minutes swimming against atypically strong currents before we were inside the break. As I mentioned previously, this was fortunately a relatively benign situation. We had left plenty of reserve air to inflate our BCs, deploy safety markers, or even re-submerge if necessary. Other than an unplanned workout, the only real consequence incurred was a bit of sunburn on my head and neck. That being said, the fact that I was SO FAR deviated from my intended reference point is very concerning. If any number of variables were different (daylight, equipment failure, rough chop, seacraft, etc.) this could have easily become a dire situation. My question here is: Other than improving navigation distances (#1), are there any common practices for "adjusting" dive planning in order to account for water currents?
Apologies if any of my questions are incredibly basic; these are just things that either weren't discussed extensively during my training or that I've just failed to adequately retain since I had not needed to apply them until now. I'm not the most experienced diver, but I'm smart enough to know when I've made a dumb mistake, and this dive seems to be a perfect example of just that.
Thanks in advance for any guidance in making this a learning experience!
-Kirk
I'm a relatively new diver - I've been certified for 4 years, but sadly my schedule and budget do not allow me to get out nearly as much as I'd like! I was able to squeeze in a beach dive this past weekend. It was the first time ocean diving from shore for both my daughter & I.
While the dive itself was relatively uneventful, I recognized some poor judgement on my part that raised some questions regarding navigation. Fortunately, the consequences ion this case were minor, but the need for improvement seems pretty obvious to me...
#1: Measuring and tracking distances underwater.
During this dive, we were advised of the locations of several reefs using visual points of reference both on and below the surface. We aligned with a particular buoy, surface swam until we were parallel with the end of a rock jetty, and submerged. At depth, we proceeded due east for approx. 50yds and found the first reef, exactly where we were told it would be. The remaining waypoints were simply approximated distances ("when you get to another sand bottom, swim another 25yds, you'll hit the next reef", etc.). In this case, the reference points were pretty idiot-proof, but my question is: Hypothetically... If we went off-course and "missed" our landmark(s), how would we confidently know HOW far we'd swam? Using only my estimations, the directions we'd been given were pretty spot-on, but I can easily see how simply "using my judgement" could lead to a dangerous situation, especially in a poor-visibility environment. We were diligent about using our compasses to ensure we would be able to accurately return on the same course, but as for specific distances, I feel like there's surely a better method than basically estimating how far we'd travelled between points A and B. I do carry a finger reel, but it is relatively limited in length (60', I believe). This particular dive being in Florida, I was also using this line to tow our SMB. I've done guided wreck dives in which our DM had used lengthy lines as guides, but truthfully never considered (perhaps naively) one of those large-capacity line reels to be "standard" gear. Using a similar line reel, I can see how distances could be easily measured; I guess what I'm asking is what, if any, alternate methods should I be prepared with to more accurately determine underwater distances?
#2: Current considerations for dive planning.
Here's where I really "dropped the ball" in terms of planning on this dive: given our shallow depth, we knew this was a no-deco outing, and mutually decided on both "turnaround" and "surface" thresholds based on air supply. Applying the "rule of thirds" and actively communicating, we executed the dive exactly as planned. Thus, you can imagine my frustration when we surfaced, only to discover that we were easily 100yds asea from our original point of descent! About 10 seconds after deciding to snorkel ashore, the reason for our miscalculation became painfully apparent: I had failed to account for the strong rip current when applying our return to shore! Even after moving longitudinally to dodge the rip zone, we ultimately spent over 30 minutes swimming against atypically strong currents before we were inside the break. As I mentioned previously, this was fortunately a relatively benign situation. We had left plenty of reserve air to inflate our BCs, deploy safety markers, or even re-submerge if necessary. Other than an unplanned workout, the only real consequence incurred was a bit of sunburn on my head and neck. That being said, the fact that I was SO FAR deviated from my intended reference point is very concerning. If any number of variables were different (daylight, equipment failure, rough chop, seacraft, etc.) this could have easily become a dire situation. My question here is: Other than improving navigation distances (#1), are there any common practices for "adjusting" dive planning in order to account for water currents?
Apologies if any of my questions are incredibly basic; these are just things that either weren't discussed extensively during my training or that I've just failed to adequately retain since I had not needed to apply them until now. I'm not the most experienced diver, but I'm smart enough to know when I've made a dumb mistake, and this dive seems to be a perfect example of just that.
Thanks in advance for any guidance in making this a learning experience!
-Kirk
