navigation back to the boat

[azwarian]

hi guys,

ive been diving for a while now and still have problems being able to navigate back to the boat / ascent line when diving.... im able to take a general heading on my compass but find once i start swimming around i get disorientated fairly easily and find it very difficult to track just how far off my return point i am.

any tips or advice for improving and being able to find my way home more often?

thanks a million

 

[fdog]

Take your compass and a large towel to the park.

Work on some simple navigation, using the compass and counting steps. Then, add the towel over your head.

...Bring a friend to stop you from stepping on "doggie landmines"...



All the best, James

 

[fisheater]

What James said, with the addition of noting the depth of the anchor and the topography around it.


Sent from my iPhone using Tapatalk

 

[BrianKon]

Try this....

When you descend take a depth reading at the bottom of the mooring/anchor line. 35 feet lets say. Go dive, use your compass for general headings and such. you should be able to tell if your north, south, east, west of the mooring line. Swim along the depth you recorded at the beginning of the dive toward the direction of the boat, you should run right into it. If however the depth is constant in the area of the mooring, this won't work. Instead use your Nav Planner, if you don't have one I would suggest taking an Underwater Navigation course (not the AOW Adventure dive) Make mental notes of bottom topography, etc., Dive the same site 12 or more times in a few months to get your nav down. then move onto another site, you will see that it may only take 8 times at the next site to
"Learn " it, as you dive from there you will know what to look for, how to judge your distance, by air consumption, time, kick cycles(don't really use those unless it is a brand new site, low vis or I am mapping it for future reference. After 12 or so dives at the same site, you should be able to draw a map of the site from memory. When you get that number down to three, let me know...I got a job for you.

good diving to you

 

[Doubler]

All good info so far but let me add a couple of pointers. Descend to depth and look up at the boat, is it a surface shadow or clearly visible. Remember what it looks like. Note where the boat is anchored, remember what it looks like. Note topography, pick out something distinctive, take a heading and swim towards it, once there swim about 10 yards away and look back at it. Topography usually looks different going and coming back. Do a compass check, back look every now and again and Navigation will get better. When you reach your original Nav point start looking for anchor on bottom, anchor line and boat shadow. After a while it will become second nature and you won't need to kick count.

 

[Frosty]

I agree with fdog but I'd go further. just try navigating anytime anyplace whilst walking. Of course if you're a rigger on high then it might be a bit life shortening. You get the point though. Anytime anyplace practice using a compass.

 

[theduckguru]

1. Holding a heading is rule #1 in compass navigation. Unless you have some specific bottom references, you can't navigate back if you don't know where you are. If visibility allows, take a reading, find an object on that course and swim to it, repeat in a series.

2. Distance / time is the #2 rule, if you don't know how far you went, how do you know how far you have to return.

3. Rule #3 is to have a plan, swimming a rectangle pattern or a line out and back.

4. Rule #4, swim against current out, with current back. Swimming cross current is a tough compass problem to solve.

 

[TSandM]

Compasses are useful, but not very precise underwater. It can be difficult to estimate the amount of drift off your heading created by current or surge. But when you combine compass information with depth contour and topography, it's possible to navigate pretty well. If the viz is only 10 feet or less, it can be quite challenging to find the anchor line (and in some places, there is no WAY you are going to see the boat, or its shadow, from the bottom). If viz is extremely poor, and returning to the upline is critical, an "out and back" pattern of swimming, where you never get very far from the point certain, can be employed.

One of the things I do, because I don't get much practice in finding anchors (our Puget Sound charters are almost ALWAYS live boat), is to go all the way to the bottom of the anchor line and inspect the site where the anchor is lying, including its depth, surrounding structures, depth contour, and any remarkable things I might recognize on my return. The times I've really gotten skunked where when I failed to go all the way to the bottom and do this.

 

[Searcaigh]

Take a very long piece of string ......

 

[Garrobo]

Rent an instructor for a few days and learn how to navigate by reading a compass and the sand patterns and grooves.If that doesn't work drop some bread crumbs. If that doesn't work dive with someone who knows how to navigate or dive only with a DM in the group. In shallow reef dives you can go to the surface and look for the boat, take a compass reading and go to the general area of the boat. If you are completely lost, go to the surface and let the boat find you. Lots of ways to get back.