Mapping a reef

[nikko]

hi everyone,

I am working my way to PADI Dive Master. All I have left is my final exam and mapping a reef. Does anyone have any advice for mapping? More than doing this for Dive Master I am doing it because it is the reef I am asked the most questions about. It would be great to have a map to show/give people. Any advice would be much appreciated.

thanks.

 

[Quero]

This topic just came up a couple of weeks ago, and I think the discussion on it was pretty good. Here's the link. http://www.scubaboard.com/forums/going-pro/364004-dm-map.html

There are a few older threads on the topic as well. Check at the bottom of this thread (near the footer) for some links to related threads that might have more ideas.

 

[nikko]

Thanks, I'm checking it out. Apparently I put the wrong info in the search engine.

Much appreciated.

 

[Quero]

Happy to help, nikko! It's hard to know exactly what words people assign to their post/thread titles-- "divemaster" or "DM"; "map" or "mapping" or "mapping project". Sometimes, even, it's easier to simply google "ScubaBoard" and selected other key words than it is to use SB's own search feature! I just happened to remember where the recent discussion was

 

[Charlie99]

hi everyone,

I am working my way to PADI Dive Master. All I have left is my final exam and mapping a reef. Does anyone have any advice for mapping? More than doing this for Dive Master I am doing it because it is the reef I am asked the most questions about. It would be great to have a map to show/give people. Any advice would be much appreciated.

thanks.

I helped a DM candidate do a map of a reef here on Maui. To do a good job took lots, and lots, and lots of diving.

First I did the outline of the reef to sand by doing a series of straight lines from point to point. Recorded the heading and number of kicks for each straightline. Then I used Photoshop elements to enter in each straightline segment. I also entered the depths that I had recorded.

Then I went around the reef the other direction to see if it all matched up.

Then I took shortcuts from various points directly to other points on the other side of the reef to check for accuracy.

Then I went back and took bearings and distances (kick cycles) for various key features in the interior out to known points on the reef-to-sand line. Recording depths of course.

Then I looked on my map and wrote down various heading and distances between various key features and then went and checked them.

Then I did a few checks to convert my scale of "kick cycles" into real distances of feet.

None of this was complicated rocket science (other than perhaps finding a program that could easily plot straight line segments of a given bearing and distance).

===========================

Assuming it is a reef that you already know well, you can start with the known heading between various key features and then do a dive to verify the kick counts. After the dive, plot all the key features that you have located and that should get you started on the repeated cycles of "measure, draw, verify".

 

[The Kraken]

Get some good assistants (may have to bribe them with food, beer, etc.)

Get a BIG slate.

But a 300' fiberglass tapemeasure.

Make sure you have a good compass.

Run the tape, shoot the azimuth, record and move on.

AND STAY OFF THE REEF.

the K

 

[SCUBA482]

While this is a fun task, due to the diving, don't overthink it...get some charts, look at them and use Google Earth to find a date where you might be able to see the reef on a good viz day...you can get some rough headings and distances from Google Earth to at least get some shore info as well...place a blank piece of paper over your monitor and trace...then go dive and after verifying some depths, start charting process...measure, compass headings and move one...I would try to add extra detail in areas of particular interest so that you may share those at a later date...think of it like trying to give directions to somebody by only being able to use landmarks..cuz underwater those are important, especially the most distintive one...above all else have fun doing it!

 

[BLUESEASONBALI]

When we map our divesites for the DM training, we make sure that it is conducted over a series of dives and not just one session. I tell the students to make the first few dives as simple as possible when they are setting out a grid and taking very basic orientations, topography and depths. Once this grid is set, with a very distinct start/finish point the following dives can be used to 'fill in the gaps'. Using the U shape search pattern the trainees will work in buddy team again mapping the topography, and relief of the location with more detail than the first few dives. The whole are must be covered with this details o that the contours and the base layer of the map can be produced and shown to one of the Instructors at this point.

Once this base has been approved, again the DMTs will head to there starting point and use what ever method they see fit to map points of interest; coral bommies, sand channels etc using techniques such as arm spans, Kick cycles and tape depending on the conditions to measure the distance between certain points.

The great thing about the DMTs having their own instructor manuals now is that they can clearly see what the performance requirements for the component is and so wont dare hand it in until they know they have all been met!

http://www.facebook.com/home.php#!/blueseason.bali