Another New Diver With Some Questions!

[usmarine_7]

Thanks everyone for the info. I was sent into an air consumption black hole. Everything from complex math to simple conservative solutions. Since i will not be taking a calculator with me on dives i will see how the "rule of thirds" works out. I also liked the solution to have 100psi for every 10ft for your accent. This is all great info and am sucking it up like a sponge. Thanks!

 

[Vicksburg Diver]

Another option that helps get you from the wreck/reef back to the anchorline is to drag a line in the sand from the anchor to the wreck/reef. Once on the wreck/reef stop and get your bearings as to where you came in (what part of the boat or any features on the reef). If you begin your dive with the wreck/reef on, say, your right side then when you turn and come back it should be on your left. Of course, always start your dive upstream against the current. Practice compass runs by making increasing larger runs on subsequent dives until you get the hang of it. Another tool is to map out the wreck/reef on a slate and include headings and reciprocals (180 degrees) so that you know where you are at any given point.

 

[nimoh]

Thanks everyone for the info. I was sent into an air consumption black hole. Everything from complex math to simple conservative solutions. Since i will not be taking a calculator with me on dives i will see how the "rule of thirds" works out. I also liked the solution to have 100psi for every 10ft for your accent. This is all great info and am sucking it up like a sponge. Thanks!

no need to take a calculator. You do your gas planning on the surface and then know your turn pressure and minimum gas. If you can't remember those numbers, write them down on a wrist slate or wetnotes.

 

[DivemasterDennis]

Congratualtions on your certification! From a blog post of mine, here are suggestions on navigation:
... Navigation is second only to buoyancy control on my list of important skills to master in order to be a competent diver. (there are of course more skills on the list) I enjoy working with advanced open water students and navigation specialty student on these skills.
Here is my short list of important navigation tips:
1. Believe the compass.
2. Navigation involves vectors which have both direction AND distance.
3. When diving on you own in conditions that require good navigation, a slate is an essential tool. Use it to note your course. Some people who do navigation skills work regularly can maintain a good mental chart, but a slate is a must for most of us.
4. Distance determination is harder to master than direction determination. All the suggested methods are useful: kick cycles, time, air consumption. Unfortunately, none are constant. Use the method that is most constant for you, which will vary with the conditions you are diving. Each of them requires lots of practice to be mastered. When possible use landmarks- they don't move.
5. However your compass is mounted, (and I'm ok with console mounts or compass only on a retractor) holding your compass level is important.
6. Make use of landmarks to confirm your location.
7. Always be thinking about how to make your navigation more precise.
I like to navigate from object to object when possible. Example: we went off shore at 80 degrees for 5 minutes to the big coral head (note on slate) The we went more or less 145 degrees to the main reef, taking 3 minutes, where the big elkhorn coral was (note on slate). Then we went on a course more or less 180 degrees for about 10 minutes, looking at the reef. Now I could try to navigate straight back to our point of origin (about 330 degrees for 14 minutes) OR... I can reverse my direction by going on three simple reciprocals: 00 degrees, then 315 degrees, then 275 degrees, using the landmarks and time for confirmation. The second way is easier.
If you want to be a good and accurate navigator, practice with your compass on every dive, even if you are being led by a divemaster. It's a little work, but it's actually nice knowing where you are and how to get home!
DivemasterDennis

 

[TSandM]

Congratulations on your certification, and kudos to you for thinking ahead and gathering information to be prepared to deal with issues that might come up in your diving.

Getting back to an anchored boat can be a challenge. If the anchor is in the depth range where you are going to dive, it is good to start the dive by going down the anchor line. Follow it to the end! Note the depth of the anchor and study the features around where it is. If the site has any depth contour to speak of, returning to the depth of the anchor is a very good way to improve your chances of finding it.

If the viz is poor or you are very inexperienced, stay close to the anchor (assuming depth permits this). Make little forays out away from it, and then come back and try another direction. One of the things you'll learn about diving is that you don't have to cover a lot of ground to see a lot of interesting things; in fact, swimming too fast is a way to miss many camouflaged species!

If there is well-defined structure at the site, you can use that for navigational information. "Reef on the left shoulder going out, reef on the right shoulder coming back," was the dive briefing we got on all our dives in the Red Sea

If you are unfortunate enough that the boat has dropped the anchor somewhere where you don't want to go (as was the case with one of my dives this last weekend), you have to study other things you can use to make your life easier. If there is current, make sure you dive into the current, so that, if you surface away from the boat, the current will carry you back down to it. Try to study the place where you drop, to see if there are any easily recognizable features, and again, note the depth.

Finally, find out what the boat's procedure for retrieving a diver who can't make it back is going to be. Some boats have skiffs for picking up errant divers, but some don't, and will have to wait until they've got everybody who DID make it back on board, before pulling the anchor and chasing the lost ones. I would say that sort of boat is not ideal for beginners, but anybody diving off such a boat should have a large inflatable marker with them, so that if they can't get back, they can stay visible until the boat can come and get them.

 

[DevonDiver]

Thanks everyone for the info. I was sent into an air consumption black hole. Everything from complex math to simple conservative solutions. Since i will not be taking a calculator with me on dives i will see how the "rule of thirds" works out.

It gets much simpler if you start working in metric.

Just saying...

 

[freewillie]

Here's a funny story about diving on boats. I had just completed Navigation and AOW certification. My daughter and I were on a boat diving just off Point Loma in San Diego. We descended along a buoy marker and then made our way along a rocky reef. After swimming around for while it was time to head back. I turned us around using my compass, and kept the reef along the opposite side. When we reached the end of the reef I couldn't find the buoy marker.

I swam a few yards past where I thought the marker was, then decided we should surface and take a look for the boat. We I broke the water my heart froze, I couldn't see the boat anywhere. I'm starting to get a little worried when my daughter started laughing. I had surfaced 15-20 feet beyond the boat but it was behind me where I was looking. I was in the right spot and had brought us back after all. Trust the compass.