Navigation question

[Nosnhoj]

Hi, recently certified and can't wait for my next dive!

When I dove for the OW certification, I followed the instructor around the bottom for the 40(ish) minutes we were down there. Me, I was busy taking in all the new sights while following him. My question is - how did he know where the boat was? This particular day the visibility was not great - yet when i gave him my 1/2 tank sign, he made a few turns, we swam for a while, and before i knew it we were back under the boat... how the hell did he find it so fast?

What is the normal protocol? do you surface and look for it? or should you always know where it is while you are underwater.

thanks
G

 

[Doppler]

The chances are good that your instructor has dived in that spot many, many times and was able to use "landmarks" that would be unnoticable to you, to guide him back to the ascent line. The technique is called Natural Navigation... it's the same as an experienced hiker knowing a trail or a city bike courier knowing the shortest way to get uptown. It's called experience.

The normal protocol is to know where it is safe to surface.

Oh, and welcome to the underwater club.

 

[Teller]

No you do not surface unless you have to and if you do keep in mind that you are really doing two dives if you decide to get your bearings and decend back down again. You have two options, shoot a heading with a compass and follow it while keeping track of your kick cycle and then turn the dive or use natural navigation by using features around you. A little practice goes a long way. Take a navigation class.

 

[eponym]

Hi, recently certified and can't wait for my next dive! [snip] What is the normal protocol? do you surface and look for it [the boat]? or should you always know where it is while you are underwater.

Congratulations and welcome to the sport!

Occasionally dive teams lose track of the way home. When you pop up to the surface to take a look around, get a compass bearing, and descend to continue your dive toward the boat or shore, that's called "prairie dogging."




Have fun,
Bryan

PS. Good navigation skills are priceless. You need to work at it (starting with a good mentor or good Nav course + instructor). Every dive is an opportunity to improve.

 

[freewillie]

Your instructor likely used combination of compass and natural navigation. It also helps that he has multiple dives in same location.

As a new diver you should always orient yourself and position before you descend. Take a compass reading and note where you are in regards to the boat/shore. Once underwater note what heading you are taking, but look around to see if there are any distinctive natural landmarks from where you are starting. A clump of rocks in a formation, bunch of seaweed or kelp etc. Make a mental note that this is "home." Also note the depth as this also helps you identify "home."

Once you are due to turn around, go back in the opposite heading on the compass. Start looking around for the natural landmarks and see if you recognize "home." You should always have an idea of where you are and how far you have gone from home underwater. If in doubt you can always surface but this should be last resort and you should not get in the habit of having to surface to figure out where you are.

Once at the surface don't for get to look around. My first boat dive with my daughter I couldn't initially find the buoy marker. I knew we were in the right area but couldn't find the rope. When we ascended to the surface all I could see was the shore. I started freaking out as the boat was nowhere in sight. As I turned around I saw the boat behind me. We had gone about 10 ft beyond the marker and I was about 10 ft from the boat. Whew!

The best way to get comfortable is dive as often as possible and use your compass/natural navigation even if someone else is guiding you. After all, what happens if you get separated?

Good luck.

 

[TXreefer]

I listened to a thesis presentation one time where the would-be graduate student went through the process of "getting his bearings" at the Flower Gardens by taking a compass heading at the mooring bolt before venturing off into the blue yonder. We used to laugh about it because it wasn't really appropriate to include this in his thesis research rather than the results of the micro-molluscs he was studying. Looking back it was good advice to new divers especially in a new area!

 

[Dirty-Dog]

In order to answer, you'd have to tell us if the boat was anchored or not. In many places, the boat follows your bubbles. When you come up, there it is! It's a miracle!

If the boat is tied off, then as others have mentioned, the instructor will be using a compass and/or landmarks. Dive that site a few times and you'll be suprised how fast the reefscape becomes familiar to you.

 

[Jim Lapenta]

Natural nav, compass, and until you get really comfy with nav the best way is to practice and start small. Rather than setting off on a 100yd swim, turning, and coming back hoping to get within 20 yds of your start point swim shorter courses. In my neck of the woods vis is often 10-12 feet. So if you did come back to within 20 yds you'd never know until you surfaced! Better to swim a course of say 2 x vis and measure the drift if any, the distance you were off, and evaluate conditions and your technique. If you swam out 30 feet and came back 15 off with no current something is off. Now figure out what. Were you holding the compass right? IS there something interfering with it such as a metal object? Are you using even kick strokes? All these can throw you off. I see instructors doing a AOW Nav dive and telling students to swim out 25 kick cycles turn and come back. With the if you are within 20 feet it's ok BS. No it's not because they can get closer if they know how. Turns should be done precisely. Stop and turn. No big looping ones. Stay in trim when turning. And again start small and work your way up.

I learned to nav not from an instructor but a DM candidate who chose to make navigating a focus of his diving. On every dive. It seemed like magic the first dive we did. Now not so much cause I have worked on my Nav skills for going on 8 years now this July. Nav is not just seeing landmarks. It's remembering and documenting them. Taking note of a return heading before every dive. Especially those led by someone else. Because they may decide to do something stupid or that you are not ok with and you have to say bye bye and get back to the boat or shore on your own.

Nav is a skill like buoyancy and trim that should be practiced on every single dive. Taking note of distances in some way needs to become second nature as well as noting changes in direction. At first it's best to write them down on a slate or wetnotes until you get used to keeping track in your head of them. Taking a course from an instructor who really knows how to do it and is not just allowed to is a good start. Not all instructors are good at it. Some downright suck. Some will make you think you are watching magic happen. Those are the ones you need to find. They can keep their bearings in any situation. New sites are not a big deal. My first dive in Puerto Rico I convinced the DM to allow my student and I to do our own thing. He did and we went our own way and came up within 10 yds of the boat after an hour of swimming around. I admit there were a few things my student saw that I did not but that was OK. I was doing what I love. Working on my Nav skills. Better than any of the things I missed seeing in my mind. I can see lobster and eels all the time. Finding my way back that close to the boat after being down an hour with 6 course changes was worth missing them.

 

[DivemasterDennis]

I want to start by saying the term I like for divers who surface to locate the boat because they aren't sure where it is is "doing a compass check." It isn't, of course, but it sounds better than "surfacing to figure out where the heck we are." I am one of those people like Jim Lapleta's DM who loves underwater (and land) navigation , and the use of a compass, natural objects, light, sand ripples, anything available to assist in knowing where I am in relationship to where I want to be (eg, the boat.) Navigation is a developed skill. Sometimes it is easier than other times. Visibility, presence of current, distinctive features, sunny vs cloudy days, all impact navigation. I paste here my recent blog on navigation for recreational divers:

November 25th, 2011 at 09:34 AM (495 Views)

There is a really good thread concerning a navigation question in the Basic Scuba Discussion Forum started November 21, 2011. There are a lot of good tips in that thread, and to go with them, I share with them my own navigation tips for recreational divers. 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
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[Nosnhoj]

Thank you all for the replies. I am planning on the advanced open water soon and will definitely look into some navigation training. On a side note, I pick up my Atomic Cobalt on Saturday