Finding the boat

[gryder]

My navigation skills suck. Big time. On dry land I'm flat out finding my way around, underwater I'm completely hopeless.

Now, I'm not prepared to fork out for a underwater sonar transmitter/receiver set, but since the advent of digital compasses, I was kinda hoping that one might track your headings from the start of your dive and give you an approximate (and I know it would be *very* approximate since it can't cater for drift, the boat moving etc) heading back to where you started from.

Does anyone know if there are comps out there that do this or have experience with one?

 

[reefduffer]

Now, I'm not prepared to fork out for a underwater sonar transmitter/receiver set, but since the advent of digital compasses, I was kinda hoping that one might track your headings from the start of your dive and give you an approximate (and I know it would be *very* approximate since it can't cater for drift, the boat moving etc) heading back to where you started from.

Does anyone know if there are comps out there that do this or have experience with one?

You're not the first looking for a solution. There are a couple of future products everyone's been waiting for.
The most promising is Navimate, an underwater GPS system, see Navimate - GPS for Divers - Additional Information and FAQ's
Announced at DEMA 2009 for delivery summer 2010, now expected first half of 2011. It's been discussed on several scubaboard threads, use search.

The idea of inertial tracking, which is what you're asking about, has been discussed several times in the recurring "needed scuba inventions" scubaboard meme. The most promising inertial tracker project I've seen was discussed here:
http://www.scubaboard.com/forums/basic-scuba-discussions/209712-underwater-navigation-device.html starting in post #35, by user kacem78.

He seemed to have a real handle on the issues, and intent on a product. But his last post there was June 2009, and although he's been on scubaboard as recently as this past August, and there were repeated requests for updates on the project, there's no news. But you may find reading that thread generally illuminating wrt your question.

 

[Peter_C]

The most reliable find the boat tool is a reel. You can use a strobe attached to the rode, with a sausage of some kind to keep it off the bottom. The sonar units from Desert Star do work well. As a test in benign conditions, the Sport System put us about 15ft from the boat. They are electronic and not something to rely 100% on. At the least attempting to navigate by compass is still important.

One of the biggest questions to ask is what type of compass are you using and where is it mounted? For me switching to a wrist mounted SK7 (I use a DSS bungee mount), improved my navigation skills substantially. I have played with the digital compasses and was not impressed.

 

[gryder]

Thanks reefduffer, I did see that thread but valiantly hoped that something had popped up in the meantime. I've heard anecdotal reports of "pressing a button and an arrow appears in the direction of the boat" but never seem to be able track down the origin of such elusive statements...

Dive companies now seem to be using the terms "bearing memory" and "route analysis" when describing their digital compasses and with a little imagination I'm envisaging the magical arrow

There's also a Sport and Scout Homing System by Desert Star that's available but it's still quite expensive and I was hoping to find something vaguely useful wrapped up in a dive computer.

Thanks for your feedback, I appreciate your time.
Jill.

 

[gryder]

One of the biggest questions to ask is what type of compass are you using and where is it mounted? For me switching to a wrist mounted SK7 (I use a DSS bungee mount), improved my navigation skills substantially. I have played with the digital compasses and was not impressed.

I have a UWATEC SmartCOM, the compass is part of the console, and yes, I have trouble doing navigation drills in the car park with it never mind adding poor viz and a bucket load of surge!

The other problem is that I never dive in straight lines, I love the critters and chase turtles and sharks (in a nice way) and often end up going round in circles so something with a bearing memory would probably serve me well.

 

[thanksforallthefish]

I have a UWATEC SmartCOM, the compass is part of the console, and yes, I have trouble doing navigation drills in the car park with it never mind adding poor viz and a bucket load of surge!

The other problem is that I never dive in straight lines, I love the critters and chase turtles and sharks (in a nice way) and often end up going round in circles so something with a bearing memory would probably serve me well.

I have always had difficulty with the compass in my smartcom, in fact with most scuba compasses, so i now use an orienteering compass

I realise this wont help your quest, but may be an alternative to your current compass.

 

[Lee Taylor]

I suggest all divers learn how to use a compass. In my opinion the compass is an excellent tool. It works quite well in open terrain. It will keep you going in a straight line. Of course, you can at any time reverse, or change the "direction" of your straight line (or bearing as they say). Use is to your advantage. The only difficulty I have with the compass is estimating the distance traveled.

Navigating shipwrecks in very low viz water is a different story. First off, the compass will not work due to the abundance of metal. My advice on shipwreck navigation, in low viz, is do not stray off into an abundance of twisted metal. You will quickly get lost that way. Instead, find the upper or lower edge of the ship and follow it forwards and backwards. You can then stray (a little, but not far) from the edge when you arrive at something interesting.

 

[RJP]

My suggestion: take up wreck diving!

1. There's a rope in the water
2. There's a boat on either end of the rope
3. Follow the rope in either direction
4. If it takes you to a boat on the surface, you're good
5. If it take you to a boat on the bottom, reverse direction
6. If both boats are on the bottom, navigation is the least of your worries

 

[CPH]

I have improved my navigation alot since I started to use my Galileo Luna. I find it a fantastic tool. I still have an SK7 and a Uwatec standard compases, one of which I carry in my leg pocket as a spare.

 

[Hawkwood]

My suggestion: take up wreck diving!

1. There's a rope in the water
2. There's a boat on either end of the rope
3. Follow the rope in either direction
4. If it takes you to a boat on the surface, you're good
5. If it take you to a boat on the bottom, reverse direction
6. If both boats are on the bottom, navigation is the least of your worries

How do you come up with this stuff?!? I just about lost my coffee. I have visions of that scene in Fool's Gold with the boat slowly settling on the bottom bethind them.