Northwest Dive Club

Hey Divers,

Being a newbie to diving I am trying to rack up my "best practices" knowlege bank. Outside of a refresher on using a compass, navigation was largely an untouched subject during my open water course.

Can folks refer me to any online published documention/articles/threads? OR, go ahead and share some of your tips which you find useful.

Thanks,
John

i'm interested in this too! :-)

Here are two "starting-out" materials I hav found so far..

Excert from an Underwater navigation book:
http://www.hammerheadpress.com/Media/PDFS/compass.pdf

Compass use 101:
http://scuba.about.com/od/beginners/a/compass.htm

are those hammerhead press books good? i was actually on that site earlier today and saw a few that looked interesting.

the best practical navigation by far around here is to swim contours and to track your time out and back.

for example, one time in cove 2 we went 25 mins south at 100 fsw, 10 mins up to 30 fsw, and 35 mins back slowly going from 30 fsw to 10 fsw and overshot, swam under the piers and wound up in cove 3. oops. 35 mins > 25 mins would have told me that we were making a navigation error.

more recently i did a dive where we dropped in the water someplace off the west side of alki swam down to 60 fsw, did 25 mins north and 25 mins back and go out within probably 30 feet of where we went in even though we swam over nothing but featureless sand and had no landmarks. the trick is to note all the times when you start and stop a leg of the dive.

and typically divers swim at a pretty consistent pace which is around 50 fpm.

oh, and natural navigation using the ripples in the sand is really convenient for the times when the slope of the divesite isn't enough to orient yourself (e.g. edmonds underwater park)...

Lamont has given you two some good info here. I'd add that you can also use things in the water as tools for navigation. This works better in the tropics (and is somewhat of a trade secret for DMs in those places), but you can take a small rock or piece of bleached coral (already broken off) and put it somewhere unusual, like on the center of a tabletop coral or fallen piling. This can be a marker of sorts, indicating to you that you've returned to a certain point (at which point you'd turn or ascend, etc.).

It is also useful to take note of shadows, sand ripples, prevailing currents, even water temperature and other natural clues at the beginning of your dive that aren't subject to immediate change.

Another thing you can do is run line at your entry point. On the dive I mentioned above we had planned on running line down to 60 fsw (starting at probably 10-20fsw), swimming roughly a 60 fsw contour and coming back to the line. We had no information on the site, though, so what we found was that there simply wasn't anything to tie off to. Running a timed distance one direction and the same time back worked very well, though.

We couldn't really use the object thing, either, since all we had to play with were a couple of red rock crabs, and while we could have stacked two on top of each other, i doubt they would have stayed that way.... =)

Also, pay attention to when the current changes. If you drop in just before slack current you'll see all the seaweed and other junk on the bottom switch direction when the current changes. That isn't really a navigation tip, but its often important to be aware of which direction the current is going and when it switches. If you plan a dive at alki pipeline or other areas that are mildly current sensitive like that you should see this occur as you hit slack.

These are great tips guys. Thank you for taking the time.. It's pretty clear to me why navigation doesnt seem to be tought much, nor discussed... Our best tool is our compass and watch, with our instincts and observation backing them up. Much of it in-turn is a subjective skill from diver to diver. Maybe someday soon we'll have cool underwater electronic navigation tools, but then again it would also seem developing your "skills" is half the fun..

lamont wrote:oh, and natural navigation using the ripples in the sand is really convenient for the times when the slope of the divesite isn't enough to orient yourself (e.g. edmonds underwater park)...

i did notice this when i was at edmonds and did the last part of my surface swim face down. underwater is definitely a foreign place to try to navigate, and i'm hoping to start practicing more of it as i get more comfortable. i think what most worries me is trying to navigate when the vis is limited to 1 or 2 feet.

The main thing is to use your compass on every dive. To this day I use it every dive. Even at cove 2. You never know when your compass dicides to take a dive [pun intended] Also learn to use your compass the same way every time.

I have watched divers tie themselves in a knot because one time they look through the side window and the next time look down on the compass.

No fair telling those DM tricks. How do you expect use to keep the newbies in awe of us.

aquanautchuck wrote:No fair telling those DM tricks. How do you expect use to keep the newbies in awe of us.

You're right, my lips are sealed from this point forth for the benefit of our new buddies' amazement.