GPS?

"ajtessier" <ajtessier@worldnet.att.net> wrote in message
news:3pDIi.115531$ax1.101972@bgtnsc05-news.ops.worldnet.att.net...

> It's been on my wish list for years! I would love to be able to store a
way
> point when I find something interesting underwater, or just to see where
> I've been on a dive. I know the signal doesn't penetrate water but since I
> need to tow a dive flag on most dives I think I have an (expensive)
> answer.The flag could be the antenna and the line could be fiber optic
cable
> down to a receiver.
>
> It's a TOY money is no object!

It's been done.

Guess who?

Google DEVGRU

"ajtessier" <ajtess...@worldnet.att.net> wrote:
> It's been on my wish list for years! I would love to be
> able to store a way point when I find something
> interesting underwater, or just to see where
> I've been on a dive.


> I know the signal doesn't penetrate water but since I
> need to tow a dive flag on most dives I think I have an
> (expensive) answer.The flag could be the antenna and
> the line could be fiber optic cable down to a receiver.

As Scott mentions, its been done.

However, the general problem that even this approach has is that the
dive flag is typically not directly above you, but some distance away
because you've put some scope on your line (ie, 100ft of line out if
50ft deep, etc), and unless the environment is very consistant with
which way the flag is relative to your position (wind, current, etc),
this will result in a circle of error on your indiciated position that
may not be suitable for your diving needs - - it depends on if your
waypoint is intended to find a big, obvious object (shipwreck) or
something small (particularly critter on an otherwise obscure
coralhead).

>From a technology perspective, what you really want is a GPS that's
been integrated with inertial sensors. The basic concept is that when
GPS isn't available, the inertial gyros take over to update your
position until such time that the GPS is again available. There is
some information in the Open Literature on development efforts.


-hh

"ajtessier" <ajtess...@worldnet.att.net> wrote:
> It's been on my wish list for years! I would love to be
> able to store a way point when I find something
> interesting underwater, or just to see where
> I've been on a dive.


> I know the signal doesn't penetrate water but since I
> need to tow a dive flag on most dives I think I have an
> (expensive) answer.The flag could be the antenna and
> the line could be fiber optic cable down to a receiver.

As Scott mentions, its been done.

However, the general problem that even this approach has is that the
dive flag is typically not directly above you, but some distance away
because you've put some scope on your line (ie, 100ft of line out if
50ft deep, etc), and unless the environment is very consistant with
which way the flag is relative to your position (wind, current, etc),
this will result in a circle of error on your indiciated position that
may not be suitable for your diving needs - - it depends on if your
waypoint is intended to find a big, obvious object (shipwreck) or
something small (particularly critter on an otherwise obscure
coralhead).

>From a technology perspective, what you really want is a GPS that's
been integrated with inertial sensors. The basic concept is that when
GPS isn't available, the inertial gyros take over to update your
position until such time that the GPS is again available. There is
some information in the Open Literature on development efforts.


-hh

"ajtessier" <ajtess...@worldnet.att.net> wrote:
> It's been on my wish list for years! I would love to be
> able to store a way point when I find something
> interesting underwater, or just to see where
> I've been on a dive.


> I know the signal doesn't penetrate water but since I
> need to tow a dive flag on most dives I think I have an
> (expensive) answer.The flag could be the antenna and
> the line could be fiber optic cable down to a receiver.

As Scott mentions, its been done.

However, the general problem that even this approach has is that the
dive flag is typically not directly above you, but some distance away
because you've put some scope on your line (ie, 100ft of line out if
50ft deep, etc), and unless the environment is very consistant with
which way the flag is relative to your position (wind, current, etc),
this will result in a circle of error on your indiciated position that
may not be suitable for your diving needs - - it depends on if your
waypoint is intended to find a big, obvious object (shipwreck) or
something small (particularly critter on an otherwise obscure
coralhead).

>From a technology perspective, what you really want is a GPS that's
been integrated with inertial sensors. The basic concept is that when
GPS isn't available, the inertial gyros take over to update your
position until such time that the GPS is again available. There is
some information in the Open Literature on development efforts.


-hh

"ajtessier" <ajtess...@worldnet.att.net> wrote:
> It's been on my wish list for years! I would love to be
> able to store a way point when I find something
> interesting underwater, or just to see where
> I've been on a dive.


> I know the signal doesn't penetrate water but since I
> need to tow a dive flag on most dives I think I have an
> (expensive) answer.The flag could be the antenna and
> the line could be fiber optic cable down to a receiver.

As Scott mentions, its been done.

However, the general problem that even this approach has is that the
dive flag is typically not directly above you, but some distance away
because you've put some scope on your line (ie, 100ft of line out if
50ft deep, etc), and unless the environment is very consistant with
which way the flag is relative to your position (wind, current, etc),
this will result in a circle of error on your indiciated position that
may not be suitable for your diving needs - - it depends on if your
waypoint is intended to find a big, obvious object (shipwreck) or
something small (particularly critter on an otherwise obscure
coralhead).

>From a technology perspective, what you really want is a GPS that's
been integrated with inertial sensors. The basic concept is that when
GPS isn't available, the inertial gyros take over to update your
position until such time that the GPS is again available. There is
some information in the Open Literature on development efforts.


-hh

in article 13f47q5brl1dra7@news.supernews.com, Douglas W. "Popeye" Frederick
at Popeye@finalprotectivefire.com wrote on 9/20/07 3:20 AM:

> "Chris & Colleen" <vze4y5gy@verizon.net> wrote in message
> news:C315D7C3.64AB%vze4y5gy@verizon.net...
>> I've been out of diving for 2 years, and my equipment, well, let's just
>> say
>> my buddies call me the swimming museum...
>
> Your buddies are on crack.
>
They are? Thanks for explaining their behavior.


>> Are there any new dive computers that incorporate GPS software? I'm not
>> talking about being able to locate your favorite wreck from the dive boat.
>> I
>> mean underwater navigation without reels, etc.
>
> I hope you live.
>
>


That's funny. I hope I do too! I assume you assume that old equipment is
crappy. Seems to me that my old polished brass regs are more damage
resistant than these new plastic pieces of crap that are made in China,
probably on the same assembly line as lead-painted Barbies... But I digress.


Thanks for the info everyone.

Chris

[ICE]

You can also get:

Waterproof GPS: $170
Lowrance iFINDER H2O Waterproof Mapping WAAS GPS - 11215 - BoatersWorld.com


Float/Flag: $45
Inflatable Flag-N-Float, Accessories: Floats, ScubaToys, Inflatable Flag-N-Float

**

Set the gps to track every 5 minutes, put it in the storage compartment.

Works great for shallow dives :)