Underwater Navigation. Where to start.

[Gary D.]

Here is where we start our guys.
http://www.scubaboard.com/gallery/showphoto.php/photo/54844/cat/500/ppuser/2714

Gary D.

 

[Scuba Sciences]

Hello,

I would get yourself a compass, take a Navigation course from your LDS and practice on land first. I know when I was learning to Navigate it helped me to practice in my back yard to get used to the headings, turns, etc., then moved on to the pool, then the Ocean. It takes a lot of practice, as least it did for me. Good luck!

Tina
Scuba Sciences, Inc.
www.scubasciences.com

 

[riffdiver]

Here is where we start our guys.
http://www.scubaboard.com/gallery/showphoto.php/photo/54844/cat/500/ppuser/2714

Gary D.

Thanks. That is something.I just hope no one sees me like that. In NY, I will get arrested in no time.
But the advise is very "sound". Thank you again.

 

[riffdiver]

Now, about that Compass. Many people on this board are talking about Suunto SK7. It's not chip. Is is because it's good or fancy? If it's good, I can understand the price. If it's just AS good, there are less expansive models. Sherwood, for example.

Your inputs, If I may. Thank you.

 

[JahJahwarrior]

that article is so right--I am so mad that the babylonians divided the circle into 360 degrees. I keep looking like an idiot in math class becuase I mix up days of the year and degres of a circle. No joke. You must question one's sanity when they politely raise their hand and ask if this is a leap circle.

 

[ClayJar]

You need to go into something dealing with 360-day fiscal years. Then you can be content.

(Is a leap circle one of those Pagan rituals?)

 

[NJMike]

I'm getting all my first set of gear for Christmas and next year one of the things I'm going to practice on is navigation.

I will be diving mostly at Dutch Springs, a scuba lake in PA. One of the first things I'm going to try is going down to the 25' platform, taking a compass reading and then swimming in that direction for a given amount of air pressure, i.e. swim until I use 500 psi. Then I'll turn around and head directly back. Hopefully I'll be back at the platform after using another 500 psi.

The good thing is that no matter if I miss it, I'm in a safe environment and not concerned about getting lost.

Also, I thought the idea of practicing on land first was good. Think what I will do is put something small on the ground where I start...so that I have to be close to see it when getting back to the starting point. That way I won't unconciously cheat as I'm making the last leg back to the starting point.

 

[Hawkwood]

However, shooting a 20 degree azimuth from the swim platforms, fin cycling for 400 feet and seeing the outline of that "old bus" emerge from the murk when you've done it right is priceless. Especially if you follow it up with navigating your way back to within 20 feet of your entry point.

Low visibility dives simply force you to pay attention to your skills.

For what's worth,

Jan

Boy do I agree with that. Last time out I navigated from one marker bouy to a second bouy - hit that one right on - then took a bearing to take us across a submerged river channel. When we got to the far side of the channel we turned course and followed the side of the channel for 100 cycles then turned around. 100 cycles back I took the recprical bearing back to the second bouy. Made it within a few feet! Surprised myself to no end. Even got a high five from my son - hard to impress a "know it all " 18 year old - that was priceless. At least there is one thing his old man is better at!

Navigation is one skill I try to practice each time out, even if it is just a simple "out and back". We dive in fairly low visibilty conditions as well.

 

[Doc Intrepid]

Thank you, everyone. I understand the concept. I need "How To's". I'm looking for any good book for navigation underwater. Hands On sort of thing.

Here are a couple things to keep in mind as you (mentally) practice:

* Navigation in the open ocean is conceptually more like navigation in an aircraft than land navigation. The reason is that once you leave confined water (quarry or pool) the water itself moves and begins to act on the diver.

* It is common in open ocean to hold one "heading" or compass azimuth, and kick for a counted number of kick cycles, but actually ascribe a different path across the ocean floor - due to current blowing you off course. You wind up "crabbing" into the current: actually you are moving sideways or 'diagonally'.

* To factor water movement into your calcs, remain motionless and note how quickly you are moved, and in which direction, by currents or tides. (Hint - tides will blow you in one direction when the tide is coming in, and the other direction when the tide is ebbing.) You compensate for that influence by adding or subtracting a few degrees to/from your desired compass heading to swim "into" the direction of the current or tidal flow.

* As the others have said, the best way to become skilled in your area is to practice and be aware of the water movement where you dive, so your estimations regarding how many degrees to add to/subtract from the heading or compass azimuth you're going to follow become more spot on over time.

* In order to know how far you've gone along any specific leg, you count kick cycles. This involves setting up a 50 yard line underwater and moving along it counting cycles and dividing to establish your personal "feet forward per kick cycle" measurement. Again like aircraft, however, with "headwinds" and "tailwinds", be aware that currents will impact how far you travel with each kick cycle. Two divers keeping count are a better bet than just one...

* For optimal precision kick cycles should be recounted over time - on more than one occasion under more than one set of circumstances.....changes in gear, changes in location (currents) etc. can change your kick cycle count to various degrees.

* Finally, in situations where navigation is critical PADI teaches (or once taught) the practice of swimming in teams. One diver focuses only on the compass heading and begins counting kick cycles. The second diver holds onto the first diver's tank valve and does a number of other things to include ensuring that both divers remain at a constant depth (neither ascending or descending as currents impact the divers), tracks elapsed time, and remains aware of landmarks or topography (ripples in the sand, etc.), potential hazards such as nets, and/or obstacles. The divers switch off responsibilities on each leg of the navigation course.

* Like all other skills, this takes some getting used to but we used this technique to swim long distances in open ocean both during daylight and at night off Guam and with practice you can become quite skilled at underwater navigation. Like the others, I recommend you consider taking a course. There is much more to it than this, in terms of various options, tools, GPS, military applications, etc., and a skilled instructor can offer a really involved experience for you. You get out of it what you put into it.

Hope this helps,

Doc

 

[riffdiver]

Thank you, everyone! This November 18-19 I will be taking my OW 1-2 dives. This is in Dutch Springs. I'm looking forward to it. Even thou I have been doing freediving for years I'm excited. I never did or will do " ...You wana bet..deeper/longer.." kind of thing, water is not new to me, but scuba diving is. It's tottaly different. It's weird. My mask does not feet any more, had to get different masks (three of them, by time I found more or less good fit, not perfect thou). Breathing in the pool, one push awy from surfice is one thing, breathing at depth, is another story. Specially, when you learned not to breese. This weekend will be "Make or Brake".

Again, thank you, everyone.