Digital Compass??

[AevnsGrandpa]

Hey all,

Is there such a thing as a underwater digital compass?

During a dive on Saturday, I was practicing some nav skills with 2 other divers and we all started at the same point, decided on the same heading and wound up 5-10 yards apart from eack other when we finally came up. (Yes I know, that is why you practice) But this lead me to thinking that if you are say 100' from your destination and you are just a few degrees off plus or minus, you will be way off by the time you get 100'. The ring on my compass and even the hash marks on the inside of the compass are not super accurate so I was thinking if you had a compass with a digital dislpay and even a small site to look through you could be much more accurate...

Maybe a DIY project!!

Jeff

 

[Dryglove]

Scubapro / Uwatec used to make a digital compass.

 

[MechDiver]

Scubapro / Uwatec used to make a digital compass.

Yea, there were one or two more out there also. Very expensive and, evidently by the lack of them now, didn't work very well.

 

[AtomicWalrus]

Hey all,

Is there such a thing as a underwater digital compass?

During a dive on Saturday, I was practicing some nav skills with 2 other divers and we all started at the same point, decided on the same heading and wound up 5-10 yards apart from eack other when we finally came up. (Yes I know, that is why you practice) But this lead me to thinking that if you are say 100' from your destination and you are just a few degrees off plus or minus, you will be way off by the time you get 100'. The ring on my compass and even the hash marks on the inside of the compass are not super accurate so I was thinking if you had a compass with a digital dislpay and even a small site to look through you could be much more accurate...

Maybe a DIY project!!

Jeff

It's pretty easy to end up off course when you're navigating, no matter what type of compass you're using. Instead of going the entire 100 ft just off your compass, try to navigate between several reference points along your route to minimize errors. Also, I usually try to bias myself to one side of my intended target. For example, swimming to a wreck over a long distance underwater, if the wreck was on a south heading, I'd instead slightly south-west. Then once I've covered the distance underwater, I'll head east and usually find the wreck on that bearing.

 

[Seabear70]

There's always drift to consider. A compass tells you which direction you are pointed in, not which direction you are moving.

So, if you are swimming a little sideways while following a compas, you may not know it.

 

[AtomicWalrus]

There's always drift to consider. A compass tells you which direction you are pointed in, not which direction you are moving.

So, if you are swimming a little sideways while following a compas, you may not know it.

That's true, and another reason to try to break up long distances into a series of smaller waypoints. Of course, that's pretty difficult if you're navigating over a featureless bottom, which is why it's good to intentionally bias to one side of your target as well.

 

[AevnsGrandpa]

Thanks for the input from you all.

Most of my diving has been in quarries with at most 15' vis, I do normally make shorter stops when navigating. Good point though about the compass tells you where you are pointed not the direction you are going!!

Jeff

 

[JDostal]

One of my friends has a digital compass - it was a Scubapro/Uwatec. It had a cool gadget factor, but not much else going for it. It was very slow to "refresh" your direction, if that makes sense, and it wasn't very detailed - the analog compasses have a much finer graduation. Some things aren't meant to be digital - compasses are one of them. It was very annoying to use to be honest.

I've got one on my GPS as well, and I never use it - I always go back to analog. And I'm one of those that usually goes for the digital version of things versus analog. This is one case where I couldn't.

 

[Jai Bar]

I have been using an Uwatec digital compass for the last three years, and I am very satisfied with it.

Its response time is similar to the time an analog compass needs to settle, perhaps a little faster.

The display resolution is 5 degress which is more than enough for UW navigation.

The compass can store 9 azimuths so you can plan a navigation course in advance and it automatically reverses the course when you ask.

It also has a timer that can measure the time you dive in each leg along the course (or deco stops, bottom timer, etc).

In addition, it is possible to calibrate or adjust the magnetic / true north, which analog compasses cannot, so you can take it anywhere in the world and just adjust it.

The battery shows 15% after three years, so it is not such an issue neither.

For diving purposes it is a great compass.
For topside navigation I wouldn't take such a compass, I'd rahter take a finer compass with resolution of minutes, unless it is for short ranges such as sport navigation, then a simple sillva compass is more than enough too. The difference is that topside one usually covers large distances, and an error of a few degrees will deviate you from the destination. Underwater, I don't think divers cover more than a few hundred meters- usually far less.