DM Map

[Jim Lapenta]

When I did mine it was one of the most fun parts of the course. Over the 20 or so dives I did to complete it I found new stuff, different points to use in navigation as not everyone needs or wants to follow the lines, and when vis gets really bad simply getting to a point where I could see the bottom contour, take a compass heading and know exactly where I was really added to my comfort level as well as those I would be leading. The mapping exercise also was not really included by my instructor in the Nav course. One of the big reasons when writing the Nav course I teach I did add a mapping requirement as well as 6 dives to complete it.

There are times now when diving new sites I take the information I learned while doing the DM exercise and create my own little sketches of the site. I don;t like being led around and when to end the dive is my decision not the DM's. So if I know exactly where I am I can choose to end the dive early or stay a few extra minutes if the op allows and lead myself and my buddy back to the entry point.

As a dive leader your situational awareness is expected to be way above the avg diver. Should not be, but with OW training the way it sometimes is some divers barely know they are wet. The mapping project as I see it and would present it to my DM candidates is another task loading exercise. This one is used to see just how attentive you are to the environment you are in as well as to the people you are diving with. DId you see that stump at the turn point we would most likley use on that dive? What was unique about it? Where was that large flat rock with the dynamite hole for the old quarry operations? How do I find it? That is the purpose of the mapping exercise as well. You should be able to describe to me in clear, concise terms how to find this point or that one. Distance, heading, depth, and if necessary draw me a sketch of the route.

 

[iztok]

p.s. I strongly advise ridding yourself of the egotism that drives the 'cold water vs warm water' superiority attitude. It shows a lack of understanding...

Devon, care to share with us a dive site map you made of cold water site with 10ft visibility?

 

[iztok]

When I did mine it was one of the most fun parts of the course. Over the 20 or so dives I did to complete it I found new stuff, different points to use in navigation as not everyone needs or wants to follow the lines, and when vis gets really bad simply getting to a point where I could see the bottom contour, take a compass heading and know exactly where I was really added to my comfort level as well as those I would be leading. The mapping exercise also was not really included by my instructor in the Nav course. One of the big reasons when writing the Nav course I teach I did add a mapping requirement as well as 6 dives to complete it.

There are times now when diving new sites I take the information I learned while doing the DM exercise and create my own little sketches of the site. I don;t like being led around and when to end the dive is my decision not the DM's. So if I know exactly where I am I can choose to end the dive early or stay a few extra minutes if the op allows and lead myself and my buddy back to the entry point.

As a dive leader your situational awareness is expected to be way above the avg diver. Should not be, but with OW training the way it sometimes is some divers barely know they are wet. The mapping project as I see it and would present it to my DM candidates is another task loading exercise. This one is used to see just how attentive you are to the environment you are in as well as to the people you are diving with. DId you see that stump at the turn point we would most likley use on that dive? What was unique about it? Where was that large flat rock with the dynamite hole for the old quarry operations? How do I find it? That is the purpose of the mapping exercise as well. You should be able to describe to me in clear, concise terms how to find this point or that one. Distance, heading, depth, and if necessary draw me a sketch of the route.

Jim, I would love to see your map of the cold low visibility site. I am looking for a good example of it. Do you mind sending me a link to it? I would really appreciate it as I too am looking to map a site that has 10ft viz and looking for ideas how to best do it.

 

[Jim Lapenta]

PM me your email. I'll attach it to the reply. I don't have a link to the map. It lives on my computer. It was done initially over the course of about 20 dives and added to over time till I stopped diving that site regularly. It is not a Rembrandt but it does what it is supposed to. Each leg pretty much was one dive. And while vis was avg 8-15 feet it was not cold as the lake is heated. Doing a map in low vis is not hard. What it really takes is patience and at times tying off a line and surfacing to confirm headings with land references. On shallow sites this not hard. Deeper dives you need to plan any surfacing for the end of the dive. Expect to do very few hour long dives at first. Short ones where you end up with accurate info is the key to not getting frustrated, and you then end up with something useful.

 

[Easdem]

I know of one DM that tied empty soft drink bottles to POI's in the quarry floated them to the surface and then was able to take more accurate distance and heading readings...Thats what I plan to do...

 

[DevonDiver]

As for the mapping my instructor has been a bit vague as to what it needs to look like, he did the same with the site emergency plan (I guess to see how far we would take it).

Perhaps he was deliberately vague...to give you the benefit of thinking through the exercise and using your initiative.

When I teach DMs, I like to ensure that the location they map is then the same location where they first get a taste for leading certified divers. They'll reproduce the map for the dive briefing, with real customers. Plan the dive. Navigate the dive.

You have to bear in mind...

1) Can you plan a dive from the map?
2) Can others use your map to plan their own dives?
3) Does it provide excellent customer service? (points of interest etc)
4) Does it cover every applicable safety issue?
5) Is it navigationally correct?

IMHO, a properly produced site map should allow any diver to plan and conduct an effective and enjoyable dive, without having been to that site before.

Create the map...and then look at it from a stranger's perspective...

I was just trying to get an idea of how deep I needed to go with detail. I think I have a good idea now.

For the emergency plan.... just imagine if you were the DM on a boat...and you got badly injured. What information would you want on that plan...so that other, lesser qualified, divers had the right directions and information to look after you and get you to medical care?

 

[scubadiver888]

OK, let me start off fresh. Andy I appreciate your comments maybe I took them a little wrong at first. Maybe I worded my original question incorrectly and maybe it's that during the DM course there have been a couple requirements that just don't seem relevent. After doing several internships still don't see relevents of several of the rquirements (maybe just haven't come accross it yet). I do understand the need to know how a dive site is layed out for planning and that alternate plan that comes into play quite offten. As for the mapping my instructor has been a bit vague as to what it needs to look like, he did the same with the site emergency plan (I guess to see how far we would take it). I was just trying to get an idea of how deep I needed to go with detail. I think I have a good idea now.

BARdiver,

When I was asked to do something as part of my DM training, if it was not clear WHY this was required I would ask my instructor. If they were vague it was often the way I asked the question. If I ask a question which requires the instructor to give me hints as to WHAT they are looking for I'd continue to get vague answers. If I asked the question WHY do we need this or HOW will my finished product be helpful I usually got a better response.

I also think what Andy was trying to say in his first response to you was that a good DM candidate would have been looking at things differently when they started diving as a potential DM candidate.

When I first started diving I had no aspirations to be a DM. How I saw a training or led dive was VERY different from how I see it now. Once I decided to become a DM I started watching other professionals as a way to learn. When they did something I had never noticed before I'd find out why. I took it upon myself to be proactive about my learning, even before I enrolled in DM training.

When I go to the Caribbean, the good guides have a whiteboard on which they draw a map of the dive site. They point out dangers and points of interest. They tell me where they will be going, what they will be point out, other points of interest, good photo opportunities, etc. This is why a DM would need good mapping skills in the Caribbean.

In my area, we use small lakes to do open water training dives. The OW class needs to know where the platform is so we tie a float to it. As DM, I have to find that platform and tie a float to it. A map of were all the platforms at a training facility is helpful. At one site there is a mineshaft. The visibility in the shaft is something like 1 INCH. If you don't have a light or OLED displays you are not going to see your computer. This is an out of bounds area for students. As a DM, if I see students heading toward it, I need to head them off. During the shore briefing, I have to warn them of it and the danger. I need to know where it is if I'm going to be pointing it out.

If we are training search and recovery, I need to know where objects are underwater to be able to have the students search for them.

These are the sort things which went into my map project. In some cases, the instructor knows where all this stuff is and I'm just doing it to show I can but in some cases, we'd take the DM training to a new location and the instructor actually wants a new map they will put to good use.

So, to summarize, ask WHY things are required. WHAT makes them important?

 

[parkerco]

Jim, I would love to see your map of the cold low visibility site. I am looking for a good example of it. Do you mind sending me a link to it? I would really appreciate it as I too am looking to map a site that has 10ft viz and looking for ideas how to best do it.

My wife and I did a 5-10'ish vis site for our DM map. After strategizing for a bit and doing a trial and error test run, what worked for us was getting a cheap surveyors tape reel from the hardware store (but waterproof -- don't want something that will stretch when it's wet) and then taking compass heading/distance measurements and penning it all on a slate (we worked out a "tug on the tape" system for when to move and setting up measurements, since all distances were beyond visibility range).

I could dig it out for you if you need another example (just PM me), but it's just a bunch of circles with numbers inside corresponding to a table with lines between and distances noted right above the lines. Took a shot off Google Earth of the site, cleaned it up and then super-imposed our map on top of it in the right place.

We found that time spent planning is inversely correlated to time spent diving -- get a good plan, think through problems you may have (how to communicate to stretch out the tape so it's a good measurement and not flapping around, how to signal your buddy as to when to move and when to hold the tape, emergency signalling with the tape since you'll be out of sight most of the dive, etc.) and then execute it. When we got back home we used a map compass and a big sheet of paper, picked a good scale (1/2" = 1' is what I think we used) and then drew the thing out, scanned it in (I could not for the life of me find a good free vector mapping program), traced the lines in Photoshop and then added annotation. Voila.

A good lesson for us was the stupid little things you overlook doing this. Like the benefit of redundant pencils =)

We had pondered doing the milk jug thing someone mentioned (mooring jugs to points of interest, getting the headings, etc.), but it didn't seem as if it would be as accurate (current) nor give us as much time actually diving the site nose-to-the-ground and would take more time than seemed neccesary. I know folks who have done it that way though and had good luck with it.

 

[hypertech]

My map was as Devon Diver described. It is not an exercise in underwater archeology or site mapping in minuscule detail, but rather, can you make a tool to use for something like a discover local diving.

I'm afraid some of the posts like Jim's may give the wrong impression. While many times, more time or more dives is a positive, I don't think this is one of them. If you want to spend 20 dives doing it because you are having fun - go for it, diving should be fun.

But, if you think this is an exercise that should or does take that much effort, you need to talk to your instructor. Either you don't understand the guidelines, you need some assistance with your watermanship skills, or your instructor needs the stick removed from his lower orifice.

For mine, I did one dive with someone familiar with the area to scope it out. Then I did some planning deciding how I would want my dive to go. Then I took the slate and mapped out the important features on the route. From this, I created the map. Then I dove the map to make sure it was right. Three dives. While I am certain my map was no work of art, it met the requirements as a tool for explaining a dive site and leading a dive.

 

[DiveNav]

...... I would really appreciate it as I too am looking to map a site that has 10ft viz and looking for ideas how to best do it.

Multibeam Echo Sounder

We actually used it to collect proprietary bathymetry data here in SoCal for the maps in our simulator. Here below an example:

The interesting part is that I submitted the map above as part of my DM mapping exercise .... and it was accepted .... as the Instructor realized that by having generated such a map and the simulator for it I could easily guide a group and probably point out any single rock in that site.


Quite an expensive project indeed


Alberto (aka eDiver)