Underwater Mapping

[CaptnJack]

Yeah the contours are from that color USGS, and they only show 10 and 50 fathoms in that range, so there isn't much detail. I wish I had more detail...

See if you can interface with Lamont's 1m DTM which is available from the UW. I don't know how he accessed it from UW/NOAA myself. He's on this board.

[smike]

well, I found the original data here:

UW - bathymetry

I'll see if I can figure out what to do with it.

S'Mike

[sheahanmcculla]

Let me know if you figure it out I don't have time to download the files right now. Did you find anything else to put on your map last night?

[smike]

I was getting too cold to do much mapping. There is a bouy that someone told me marks a boat wreck, at 130 ft or so, way too deep. The bouy only shows up on a low tide, which it was. I got one compass sighting, it is 320deg from the stairs, and about 1 1/2 x the distance from stairs to the geodome. So that should give an approximate location.

S'Mike

[CaptnJack]

Here's Lamont's translation of the bathmetry into color
http://www.scriptkiddie.org/bath/

Maybe its useful, maybe its not.

[JDR]

Hello all,
I have another question, it's about dive site mapping. First I was wondering if people could post the maps they have made so everyone can see. Also I was wondering the best method for creating your own dive site maps. I have found three ways:
1. Dive a bunch of times and hand sketch it out. (cheapest)
2. Get a handheld gps and tow it on the surface and take pictures along your dive with a camera displaying times, so you can later check the gps and note where you were at what depths. (Cheaper)
3. Buy a Hummingbird fish finder or a side scan sonar and drive over each site with a boat and transfer the information into a mapping program (very very exspensive)
Also does anyone have any tips on a good landscape software to draw up the maps, like autocad map 3d, or bryce5.

Thanks
Sheahan

Here's the method I used a few years ago. It requires multiple daylight dives in a day. Attach surface markers to underwater objects and triangulate their positions with a compass, a rangefinder and a GPS in a waterproof bag.

Supplies needed- Goodie Bag, 20 oz plastic bottles with caps (coke bottle shapped prefered) with bright marking tape inside, rigged with cotton line and you'll need 1 one ounce sinkers per bottle.

fill the bottles with water at the beginning of the dive.
During the dive attach the line from a bottle to an underwater feature you want to mark. fill the bottle with air and let it rise to the surface. Hover about 15 feet off the bottom and attach the sinker to the line. This will put some tension on the line and keep it centered over the object.
Repeat, repeat, repeat

Once on shore, take careful compass readings to each marker from a single set position (typically the entry point), measure the distance to each using the rangefinder.
Move down the shoreline to another set position (at least 200 feet away) where you can also see each marker. Take another set of compass and distance readings from that position, including the position of the original set position.
These measurements combined with a bit of drafting layout will give you the basic layout of the divesite.
You can now put on your snorkling gear and retrieve your bottles and lines assuming you used lightweight cotton line.
If you have a portable GPS in a waterproof bag you should snorkle out to take readings and set waypoints at each of the bottles and at each of the set positions you took readings from. There are several GPS geocaching sites which allow you to put in two three point locations and it will give you distance and bearing between those points.
If you used heavy cotton line you will need to make another dive to retrieve the lines and bottles (should be easy, you now have distance and bearing to each point).

[TCWestby]

Shehan and I have been discussing this and I'd like to help out. I like the marker idea, that would make it much easier to do a flat representation of the site then is seems that all you need to do is add depth.

Anyone want help I'm in.

Why cotton string?

[smike]

cotton because if you lose it it will decompose and go away, diver in a month will not get wrapped up in the line.

[smike]

I am going to look at the data from the UW this weekend and see if I can figure out how to get pieces of it into Sketchup. The data is on a 30 meter grid and the depth is in 1/10 meter - just a few inches. So should be able to get fairly nice profile if I can figure out how to write the ruby script.

[sheahanmcculla]

New map for vancouver divers.
http://www.arttomedia.com/site/Products ... ubcatid=29

[sheahanmcculla]

I still have a dream of creating a cool 3D dive map. But I saw a video on TED about Photosynth. It takes multiple photos and turns them into a 3D model. I am hoping this will work underwater.

What do you guys think? I don’t think it will work with a fish eye lens though.

Here is the video that explains what it is:
[youtube]http://www.youtube.com/watch?v=p16frKJLVi0[/youtube]

Here are some examples of what people have done underwater: http://photosynth.net/search.aspx?q=underwater

How you can convert from Photosynthe to 3D model:
[youtube]http://www.youtube.com/watch?v=TuHJUS2olyc[/youtube]


Also 4th element is following in Arttomedia’s footsteps in 3D shipwreck mapping: http://www.fourthelement.com/adventures ... ojects.php

[Nwbrewer]

That's cool and all, but wouldn't that require that you go diving to take the pictures?

I wonder how this would work taking HD video of a site and then taking stills form the video and submitting them?

[Dashrynn]

This is him secretly saying he can't kick the addiction.

[sheahanmcculla]

This is him secretly saying he can't kick the addiction.

I'm trying..but it's so hard.


What are the divers 12 steps?

[Dashrynn]

This is him secretly saying he can't kick the addiction.

I'm trying..but it's so hard.


What are the divers 12 steps?

Not sure but I'm sure denial is mentioned more than once.

[Norris]

This is him secretly saying he can't kick the addiction.

I'm trying..but it's so hard.


What are the divers 12 steps?

I'm not SURE but I think they go a little like this....

1) We admitted we were powerless over nitrogen and that out lives had become unmanageable.

2) Came to believe that a power greater then bottom time can restore us to sanity.

3) Made a decision to turn our dive addiction over to the care of Posieden as we understand him

4) Made a searching and fearless gear inventory and concluded that DAMN THIS IS A LOT OF MONEY!!!

5) Admitted to Posieden, to ourselves, and to a random dive buddy the exact nature of our wrongs.

6) Were entirely ready to have Posieden remove all of these defects of character.

7) Humbly asked Posieden to remove our shortcomings

8) Made a list of all places we have dived and became willing to log them all.

9) Made direct amends to loved ones that we left at home while diving, except when to do so would injure them or others.

10) Continued to take gear inventory and when we were done promptly INSURED IT!!!

11) Sought through surface intevals, beer and tacos to imrove our conscious contact with Posieden as we understood him wishing only for knowledge of diving safely and diving within reason, and the power to carry this out.

12) Having had a narcosis awakening as the result of these steps we try to carry this message to newer divers and to practice these principals in all of our affairs.