Underwater Compass Use

[tbone1004]

@blac86 this is an instructional video for our students. We had something ridiculous like 1k of the brass suicide clips donated, and the zip ties are a bit more convenient for this application since cave line tends to get abraded on the edges of the slate pretty easily. I've had the same zip tie on my slate since 2009 and it's working fine.

Regarding the off center lubber line. That is intentional. When the compass is off to the edge of the slate it allows a much more natural hand position with the lubber line properly bisecting the torso. If you center the compass on the slate, you have to move your arm more towards the center of the body which increases risk of inaccuracy. On the larger instructor slates, the compasses are mounted closer to the middle and act more like a nav board. The distance on the professional nav boards from hand hold to center of compass is very similar to the spacing from the clip to the center of the compass on this slate.

With this slate I have successfully blue water navigated to a buoy line about half a mile away. I can't do that with a wrist compass.

@Diver0001 your point about becoming a "real" diver is why dives 2/3/4 of our open water are all students navigating around the quarry in buddy teams with us hovering over them as opposed to them following us around

 

[blac86]

@blac86 this is an instructional video for our students. We had something ridiculous like 1k of the brass suicide clips donated, and the zip ties are a bit more convenient for this application since cave line tends to get abraded on the edges of the slate pretty easily. I've had the same zip tie on my slate since 2009 and it's working fine.

Regarding the off center lubber line. That is intentional. When the compass is off to the edge of the slate it allows a much more natural hand position with the lubber line properly bisecting the torso. If you center the compass on the slate, you have to move your arm more towards the center of the body which increases risk of inaccuracy. On the larger instructor slates, the compasses are mounted closer to the middle and act more like a nav board. The distance on the professional nav boards from hand hold to center of compass is very similar to the spacing from the clip to the center of the compass on this slate.

With this slate I have successfully blue water navigated to a buoy line about half a mile away. I can't do that with a wrist compass.

@Diver0001 your point about becoming a "real" diver is why dives 2/3/4 of our open water are all students navigating around the quarry in buddy teams with us hovering over them as opposed to them following us around

Do it how you want to do it but brass clips will get sharp on the gates with any regular Diving, zip ties break easily if twisted, and adding one more piece of gear to carry as opposed to a console or wrist compass is adding unnecessary complexity.

 

[tbone1004]

Do it how you want to do it but brass clips will get sharp on the gates with any regular Diving, zip ties break easily if twisted, and adding one more piece of gear to carry as opposed to a console or wrist compass is adding unnecessary complexity.

the video was made close to 20 years ago and because this is for a university program, cost is a huge part of it. My personal nav slate does have SS bolt snaps on them, but it is still zip tied and has never been an issue. That slate is from 2010, and has been on probably 500 or so dives.

You may call adding a nav slate added complexity, but console compasses are not accurate for long destinations, neither are wrist compasses. In either case, you still need a slate to write down bearings and preferably a map to know where you are going, so why not have the compass on the slate?

It lives in my pocket with my wetnotes if I'm diving dry, it gets clipped off to my tail d-ring if I'm not, and if I'm planning on navigating for a dive, it goes to the hip d-ring when I'm looking at something. It's well worth the "added complexity" to have all of that information available in front of you with the benefit of accurate navigation. If you just need general headings, then yeah, a wrist compass is fine, so is a console compass, but if you want to actually navigate properly, neither of those are sufficient

 

[blac86]

the video was made close to 20 years ago and because this is for a university program, cost is a huge part of it. My personal nav slate does have SS bolt snaps on them, but it is still zip tied and has never been an issue. That slate is from 2010, and has been on probably 500 or so dives.

You may call adding a nav slate added complexity, but console compasses are not accurate for long destinations, neither are wrist compasses. In either case, you still need a slate to write down bearings and preferably a map to know where you are going, so why not have the compass on the slate?

It lives in my pocket with my wetnotes if I'm diving dry, it gets clipped off to my tail d-ring if I'm not, and if I'm planning on navigating for a dive, it goes to the hip d-ring when I'm looking at something. It's well worth the "added complexity" to have all of that information available in front of you with the benefit of accurate navigation. If you just need general headings, then yeah, a wrist compass is fine, so is a console compass, but if you want to actually navigate properly, neither of those are sufficient

You've had better luck with zip ties than I have, but from my experience they break at the most inopportune times.

 

[tbone1004]

You've had better luck with zip ties than I have, but from my experience they break at the most inopportune times.

I think the difference with these is that the zips aren't crimped like they are on regulators. They are meant to be kept loose since you use your middle thru pinky fingers to hold the snap and stabilize the slate. It needs to be free to move from one side of the slate to the other and that really helps with their longevity. I have had terrible luck with others, but for whatever reason these ones work well. If you don't like it, then you can tie the snap on there however you want, same with using whatever snap you want.
The biggest thing that we try to teach is concepts, and strictly forbid monkey see, monkey do.

In this case the concept is take an accurate and easy to use land compass that can be used in the water. Mount that to a piece of plexi so you can have your map, bearings, limits, notes, pencil, etc. all on one side of the slate. The compass should be offset to facilitate a natural wrist and arm position for comfortable and accurate navigation.
Backside of the slate can have notes or whatever else on there like you would use a normal slate with your buddy.

You can choose to use whatever kind of bolt snap you want, whatever size piece of plexi that you want, attach the snap however you want, use whatever compass you want/have available, but the concept is there.

 

[Diver0001]

@Diver0001 your point about becoming a "real" diver is why dives 2/3/4 of our open water are all students navigating around the quarry in buddy teams with us hovering over them as opposed to them following us around

Yeah..... I can't really just hover above them and let them dive to see what happens. In the first 2 OW dives I'm usually busy helping them dial in their buoyancy control to adjust for the switch from the pool to open water. At the same time there are skills that need to be performed while we are swimming.... So what I normally see is that students have enough on their mind trying to get all that right to worry too much about where they are going. Asking them to navigate themselves at that point is too early to my way of thinking.

In dive 3 many are dialed in enough that I can start to let them take over navigation. At this point I tell them that they should tell me where they want to go on the tour and I'll follow their lead. I intervene if we get outside the agreed upon depths or times and I usually use this dive to be picky about buddy contact and communication..... In other words, the tour in dive 3 is really a dry run for dive 4. In dive 4 it's the standard so obviously they have to navigate. At that point they've seen the site a couple of times already so they have an idea which way is up. This seems like a normal progression to me.

Just thinking back to my own experience as a new diver I didn't really have the feeling that I had control of my diving either until I could navigate. I did obviously get a handle on it but it took a number of dives after being certified before I started to get confident about where I was going. In fact, thinking back I don't think I really had it nailed until after I took a navigation specialty. Out of pure luck I took it with someone who taught it well and it helped my diving a lot.

R..

 

[tbone1004]

@Diver0001 16 weeks, 2 sessions/week, 2 hours/session in the pool prior, plus 3 hours in the pool with their rental gear the night before the quarry all prior to OWT, combined with them all being college engineering students helps TREMENDOUSLY! I fully understand that what we do is completely unrealistic for the industry to handle.

 

[Diver0001]

In this case the concept is take an accurate and easy to use land compass that can be used in the water. Mount that to a piece of plexi so you can have your map, bearings, limits, notes, pencil, etc. all on one side of the slate. The compass should be offset to facilitate a natural wrist and arm position for comfortable and accurate navigation.
Backside of the slate can have notes or whatever else on there like you would use a normal slate with your buddy.

You can choose to use whatever kind of bolt snap you want, whatever size piece of plexi that you want, attach the snap however you want, use whatever compass you want/have available, but the concept is there.

Just a couple of follow up questions about your slate:
- How long was it before the compass came unglued? I can imagine that with those materials getting cold/warm would cause the bond to break....
- Was the compass still intact after 100 dives? Was there any particular reason you used a land-based compass and not an underwater one?
- What particular advantage do you see in having the compass attached to your slate? I normally have mine on the back of my hand so when I'm holding the slate the compass is right there anyway.... the idea being that you need to refer to the compass often but you only need to refer to the slate occasionally. If they are attached together it comes across as a bit bulky.

R..

 

[Diver0001]

@Diver0001 16 weeks, 2 sessions/week, 2 hours/session in the pool prior, plus 3 hours in the pool with their rental gear the night before the quarry all prior to OWT, combined with them all being college engineering students helps TREMENDOUSLY! I fully understand that what we do is completely unrealistic for the industry to handle.

Yeah... I figured as much.

R..

 

[tbone1004]

@Diver0001
1. compasses typically stay glued for several years. We will have a couple pop off on occasion but it's usually if the slate get's flexed. Heat expansion of the materials are similar so it's usually a non-issue
2. compasses are still intact after 100 dives. If taken really deep sometimes the fluid will come out, but they still work fine. We use land compasses because they're inexpensive, small, and mount easily to the slate. Underwater compasses are typically much larger/heavier which would limit the ability to put in a pocket, and usually necessitate two hand usage. They also typically do not have a direction of travel indicator which makes setting bearings more difficult.
3. attaching the compass to the slate allows you to view the map and upcoming bearings instantly without having to take something else out. Putting a compass on the back of the hand is fine, but still requires reference of the upcoming bearings on the slate and also tends to put the hand at a less natural position depending on how you can adjust the direction of travel indicator. Many of those compasses don't have that ability so you have to rotate your wrist to get the direction of travel lined up correctly.

again, this is not something that you would use in nice clear blue water to orient yourself. This is best used in places where you need accurate navigation due to limited visibility, or when doing complex navigation that requires use of waypoints to get to a destination.

Below is the area of the quarry that they are diving during their training. Visibility is typically less than 20ft so you can't see one end of the bus from the other. The longest leg the students are asked to dive is where you can see VW up to the North Platform. That leg is only about 150ft, but feels like a mile because there is nothing but sand out there and you can't see anything. Incredibly disorienting. With vis that bad, if you tried to do that leg with a console or wrist compass, you would likely not be able to find the north platform. A 5* deviation is enough that you would not be able to see the platform when you got out there under normal conditions. 5* sounds like a lot, but it's not that much if you have your wrist off ever so slightly.