Underwater Cache Ideas?

[+Terra•Indaga]

I'm putting some thought into an underwater cache accessable to non-divers... Any suggestions? Good experiences, bad experiences? Creative ideas? All thoughts greatly appreciated.

[+Whidbey Walk]

Absolutely, positively use a Rite in the Rain Logbook The one underwater cache I found was full of water even though ziplocks were used. However, I was able to write in the logbook.

 

[+Whidbey Walk]

Absolutely, positively use a Rite in the Rain Logbook The one underwater cache I found was full of water even though ziplocks were used. However, I was able to write in the logbook.

 

[+worldtraveler]

quote:

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Originally posted by Terra•Indaga:

...accessable to non-divers... Any suggestions? ...

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Not too deep if you want them to come back up and log it!

 

Worldtraveler

[+worldtraveler]

quote:

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Originally posted by Terra•Indaga:

...accessable to non-divers... Any suggestions? ...

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Not too deep if you want them to come back up and log it!

 

Worldtraveler

[+Terra•Indaga]

Whidbey Walk, can you tell me how the underwater cache you found was structured? Was it anchored to something above water that you found? How did it work?

[+Whidbey Walk]

I'll email you. It's not my cache and I don't want to give away anything in the forums.

 

[SNIFTER]

There is a cache here is OZ called "Fireproof" and yes it is underwater but one does not have to put on the scuba gear to get it. It is anchored with a stainless steel clip and you can get to it even in a king tide. When I found it everything in it was bone dry and I would expect it to stay that way as a lot of thought went into it. Just make sure that the cache container you use is definately watertight. Fill your bathtub and give it a test.

[Gustaf]

quote:

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Originally posted by SNIFTER:

Just make sure that the cache container you use is definately watertight. Fill your bathtub and give it a test.

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I have used a stainless steel thermos as cache container for an underwater cache. I put coins in it to make it heavy enough to stay down. It is anchored with a plactic coated wire and the depth is about 12 feet, but I tested it at 24 feet, and it was still dry inside.

[+glenn95630]

Here are some actual caches.

http://www.geocaching.com/seek/cache_details.asp?ID=5095

http://www.geocaching.com/seek/cache_details.asp?ID=6893

[+Macro]

Two thoughts here:

 

One I plan to do at some point (but feel free to borrow the idea), is to put a cache behind a waterfall. Locate any waterfall. Typically there will be either a rock wall behind it, or a boulder field under it. Either way, there are tons of rock formations that a cache could be tucked into. The running water will camoflague it pretty well. Just make sure it isnt a big fall. Too much water makes it dangerous.

 

Second, the physics involved with submerging a cache container make underwater caches a challenge. I big ammo can will not easily be submerged as it displaces too much volume. A quick solution is to fill the can with a dense material (I would use lead fishing sinker in a ziplock bag).

 

Use enough ballast to get the container to suspend in the water. Before placing the can, primer and fully paint to help avoid rusting. If you can get it "rhino-lined" that would be even better. (complete coated in rubber)

 

Attach it to an immovable object underwater with a nylon rope (wont rust or decay)

 

If you want the finder to open the cache above the surface, allow for enough rope. You could probably coil up the slack and use a velcro cable tie to keep it in place.

 

Good luck!

[lemur]

On the 30th of this month I am anchoring a peice of stainless steel on a rock at low tide. The s/s has coords etched on it of actual cache. Due to extreme tide @ full moon (-0.3ft low and 25.4 ft high) this month cache will only be accessable (dry) about 20 days / year [}].hehehe..1 week after I plant it there will be 5 ft of water over it a LOW tide.

[lemur]

On the 30th of this month I am anchoring a peice of stainless steel on a rock at low tide. The s/s has coords etched on it of actual cache. Due to extreme tide @ full moon (-0.3ft low and 25.4 ft high) this month cache will only be accessable (dry) about 20 days / year [}].hehehe..1 week after I plant it there will be 5 ft of water over it a LOW tide.

[MajBach]

I too plan on creating 'marine' caches. However, there are no tides near here. I spend the majority of the summer in my boat.I have noticed there a very few caches place in or near hot fishing spots or marine travel waterways. I plan on placing some caches on islands and submerging caches that one require a sonar device to locate. To elaborate on the latter idea, sinking a cache in say 10'-30' tied to a empty bleach bottle or something with heavy test fishing line such that the floating jug is about 5-7' below the surface. Passing over top with a sonar unit should display the bleach jug. Of course, there would be a few factors to consider first. The cache would have to be heavy to offset the buoyancy of the jug. It would have to placed such that no boat with a deep draught would snag it or in a spot where there is chance of a trolling fisherman snagging it either. It would have to be close enough to the surface though to snag it with a docking hook or to dive for it too.

As you can see, I want to encourage other boat owners to place caches too.

 

MajBach

You can't have everything.

where would you put it?

[+TAT]

Lemur,

 

I have been working on a similar cache, but don't have as much tidal range to work with (-1.6 to 11). I am planning to bury a brass bar with a nylon leader in the sand. It will look like a piece of jetsam, if it can be seen.

 

Do you plan on listing any warnings? I can imagine someone being very unsafe without knowing it.

[+Don&Betty]

To sink an ammo can, tie a cement block (or 2)snuggly to the bottom of it. It is about 0.5 cubic foot so exhibits about 31 pounds of buoyancy that has to be held down. The block has buoyancy too (not enough to float it of course) so has to weigh more than 31 pounds. Experiment.

[+RAD Dad]

I plan on placing all my caches either near the water, or even in the water. My first cache will be on an island in the river near my house, which will only be reached by boat or, if you're a nutty enough, by swimming :-)

 

ummmm....not sure what to say here....so ummm, well errrr, uhhhh, well I guess that's it.

[TheRealDesertRat]

One of the above lsited water caches, was my last found. Everything in it was bone dry. THe cache was about 15 ft under water and teh container and teh anchor system worked flawlessly. The caceh was in a perfect place and well thought out. If you want to do a water cache you should check this one out.. It was teh id 5095 up a few posts. - The Real DesertRat

[+Kevin & Susan]

quote:

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Originally posted by Terra•Indaga:

I'm putting some thought into an underwater cache accessable to non-divers... Any suggestions? Good experiences, bad experiences? Creative ideas? All thoughts greatly appreciated.

---

 

See this cache: http://www.geocaching.com/seek/cache_details.asp?ID=15323

It's truly a diver's cache, but the structure and design could be applied to a non-diver underwater cache. The owner had no log inside, so we left a diver's slate/pencil with our 'log' written on it