What kind of container to use for underwater?

[graftedoaks]

As part of a multi-stage I am setting up, I'd like to place a cache in a pond. I plan on tying the container to fishing line and anchoring it on the ground, so there is no swimming and wading required.

 

The container needs to sink, and obviously be absolutely waterproof. Any ideas or experience with a set up like this? I really don't know what kind of container to get.

 

Thanks!

[+Gustav129]

I'm doing the same thing. I have a bison tube on about 3" of fishing line on a hookless fishing lure, with a 1/2 oz steel fishing weight in between. I replaced the o-ring on the bison tube.

[+ras_oscar]

I have never personally found an underwater container, but the biggest issue is going to be somehting people can easily reclose. I'd recommend at the minimum you use write in rain paper for the log sheet, because most containers get wet eventually, even those that aren't swimming!!!

[+eusty]

A 'sample' bottle, the ones you pee into at the hospital/doctors are very watertight.

 

I've had one underwater since October, and it just has a normal paper log. Also it's easy to close

 

[+Chrysalides]

I've only found one that was completely submerged. It's another container inside a Pelican case. Even so it kept getting wet, and was eventually archived.

 

If this is part of a multistage, you can punch the info onto a piece of aluminum or brass so that even if water leaks in, it's still readable. If it's the final, you'll still have to worry about finders closing it properly even if it is completely water tight.

[+BAMBOOZLE]

I found a couple of the stainless steel water bottles that were dry after long submersion's....I would put a bison inside one of these to be sure.

[+Papa EGTH]

I've only found one that was completely submerged. It's another container inside a Pelican case. Even so it kept getting wet, and was eventually archived.

 

If this is part of a multistage, you can punch the info onto a piece of aluminum or brass so that even if water leaks in, it's still readable. If it's the final, you'll still have to worry about finders closing it properly even if it is completely water tight.

Why put anything aluminum or brass in a container? Just create your waypoint on a piece of aluminum or brass using a metal stamp kit and toss that into the water. That way you won't have to worry about watertightness. It may get scummy although your container will also. Less parts, less that can go wrong...

[+Chrysalides]

Why put anything aluminum or brass in a container? Just create your waypoint on a piece of aluminum or brass using a metal stamp kit and toss that into the water. That way you won't have to worry about watertightness. It may get scummy although your container will also. Less parts, less that can go wrong...

Good point. I tried to think of a good reason why and couldn't come up with any. Fishing line to aluminum tag to fishing sinker weight and job's done. Tag might get a film of algae growing over it that needs to be removed, but same thing will happen to container.

[+macatac1961]

Nalgene bottles work pretty good.

[+AndyT1]

If you decide to go with the metal tag idea consider using copper - it is one of the few materials that stuff like algae does not grow on underwater.

[+thesmurfinator]

Can I just mention a potential problem with the metal tag idea??

If there is any fish/animal life in the pond it could be a HUGE problem. Metals give off toxins which can be harmful to aquatic life. If you have ever owned a fish tank and used "tap safe", Water safe" or any other kind of treatment when doing water changes, that is what it is for - it removes chlorine and metals. Aquatic creature such as shrimp would find it deadly!

[+Chrysalides]

Can I just mention a potential problem with the metal tag idea??

If there is any fish/animal life in the pond it could be a HUGE problem. Metals give off toxins which can be harmful to aquatic life. If you have ever owned a fish tank and used "tap safe", Water safe" or any other kind of treatment when doing water changes, that is what it is for - it removes chlorine and metals. Aquatic creature such as shrimp would find it deadly!

I seriously doubt that enough of a metal tag will dissolve into a large body of water enough to affect water chemistry in any measurable amount.

[+akkatracker]

Can I just mention a potential problem with the metal tag idea??

If there is any fish/animal life in the pond it could be a HUGE problem. Metals give off toxins which can be harmful to aquatic life. If you have ever owned a fish tank and used "tap safe", Water safe" or any other kind of treatment when doing water changes, that is what it is for - it removes chlorine and metals. Aquatic creature such as shrimp would find it deadly!

I seriously doubt that enough of a metal tag will dissolve into a large body of water enough to affect water chemistry in any measurable amount.

+1 but I still wouldn't do it

[+BAMBOOZLE]

Can I just mention a potential problem with the metal tag idea??

If there is any fish/animal life in the pond it could be a HUGE problem. Metals give off toxins which can be harmful to aquatic life. If you have ever owned a fish tank and used "tap safe", Water safe" or any other kind of treatment when doing water changes, that is what it is for - it removes chlorine and metals. Aquatic creature such as shrimp would find it deadly!

I seriously doubt that enough of a metal tag will dissolve into a large body of water enough to affect water chemistry in any measurable amount.

+1 but I still wouldn't do it

 

When I think of the millions of hooks,swivels, spoons, sinkers, traps, boat anchors, etc that are polluting the waterways daily its hard to believe there are any fish left. Where I live there are untold millions of tons of steel in the water ( oil rigs )but strangely the fish love them and live there. Ships and other giant metal objects are routinely sunk to create artificial reefs to INCREASE fish populations.

As a life-long tropical fish hobbyists I would not put metal objects in an aquarium. I always changed a third of my tank water every week...be sure the water you add is the same temperature....no need for " water treatments". Many old timers added 1 drop of formaldehyde for every gallon of tank water during their weekly water change. I did this for 20 years with good results ( I've had good results the last twenty years without doing it )

[AZcachemeister]

If you decide to go with the metal tag idea consider using copper - it is one of the few materials that stuff like algae does not grow on underwater.

 

Can I just mention a potential problem with the metal tag idea??

If there is any fish/animal life in the pond it could be a HUGE problem. Metals give off toxins which can be harmful to aquatic life. If you have ever owned a fish tank and used "tap safe", Water safe" or any other kind of treatment when doing water changes, that is what it is for - it removes chlorine and metals. Aquatic creature such as shrimp would find it deadly!

 

Can I just mention a potential problem with the metal tag idea??

If there is any fish/animal life in the pond it could be a HUGE problem. Metals give off toxins which can be harmful to aquatic life. If you have ever owned a fish tank and used "tap safe", Water safe" or any other kind of treatment when doing water changes, that is what it is for - it removes chlorine and metals. Aquatic creature such as shrimp would find it deadly!

I seriously doubt that enough of a metal tag will dissolve into a large body of water enough to affect water chemistry in any measurable amount.

 

Can I just mention a potential problem with the metal tag idea??

If there is any fish/animal life in the pond it could be a HUGE problem. Metals give off toxins which can be harmful to aquatic life. If you have ever owned a fish tank and used "tap safe", Water safe" or any other kind of treatment when doing water changes, that is what it is for - it removes chlorine and metals. Aquatic creature such as shrimp would find it deadly!

I seriously doubt that enough of a metal tag will dissolve into a large body of water enough to affect water chemistry in any measurable amount.

+1 but I still wouldn't do it

 

I don't think there would be an issue with metals contamination unless it was a VERY LARGE tag and a very small pond.

 

Anyway, if the OP thinks it might be an issue, use a piece of rigid plastic and engrave the numbers on that.

 

OHHH, but plastics give off dioxins!

 

And forget about the lead sinker, too.

 

And while we're at it, quit breathing so much! Your exhaled carbon dioxide is causing climate issues!

[+ScoutDadNC]

I saw a video where someone was making one that floated just at water level, even when the tether-line was slack. He filled the bottom with enough concrete to get the ballast to the right levels. The cache was in a pipe and it floated in a vertical position. the top of the cache only stuck about 1" above the water.

 

As for what you are looking for. Maybe a nalgene bottle. check the buoyancy in your tub to make sure you have enough weight to sink the cache.

 

Also consider good string/rope to hold it to the shore line.

[+BikeBill]

How about a pre-form tube? They hold in soda under pressure (once they're formed) so they should stay water-tight. Or a pre-form with a bison in it?

 

Bill

[+thesmurfinator]

 

When I think of the millions of hooks,swivels, spoons, sinkers, traps, boat anchors, etc that are polluting the waterways daily its hard to believe there are any fish left. Where I live there are untold millions of tons of steel in the water ( oil rigs )but strangely the fish love them and live there. Ships and other giant metal objects are routinely sunk to create artificial reefs to INCREASE fish populations.

As a life-long tropical fish hobbyists I would not put metal objects in an aquarium. I always changed a third of my tank water every week...be sure the water you add is the same temperature....no need for " water treatments". Many old timers added 1 drop of formaldehyde for every gallon of tank water during their weekly water change. I did this for 20 years with good results ( I've had good results the last twenty years without doing it )

 

Problem is we are not talking about steel and we are not talking about fish. In fact copper was suggested which is the most toxic metal for shrimp.

Fish can tolerate quite high levels of heavy metal contamination, other aquatic creatures, such as shrimp, cannot.

The OP doesn't state the size of the pond but does say "pond" not "lake" so I would assume it is not huge.

And, just because your fish survived weekly third changes of water without any treatment does not mean they were happy or healthy because of it, it just means they survived. I've seen goldfish surviving in tiny bowls with no aeration, it doesn't mean that it what is best for them.

We in the UK drank water that came through lead pipes for decades, we survived, but it wasn't good for us....we learn, we move on, we do things differently.

Animals of all kinds can survive and even adapt and thrive in all sorts of conditions and environments, but I wouldn't knowingly harm or put at risk any animals for my own enjoyment.

If I wanted to place an underwater geocache I would find a way to do it that could not possibly endanger/harm any animal life, just like I would with any other cache placed in any other area.

Edited May 30, 2012 by thesmurfinator

[+OZ2CPU]

underwater final cache with logs and open close water tightness = HUGE PROBLEM !

will drive you as a CO and finders mad due to endless need maintenence..

 

it is MUCH better to locate final cache on the ground, where you and others can access it safely..

but the underwater item is an offset cordinate or numbers you need to find the final.

this way people must still goto your cool underwater location,

and still search after something there = funny and cool..

 

I just found a 5 x 10 incl stainless steel plate, with 4 numbers milled in it.

at just 4m deepth, and about 150meters from shore, I needed my scuba equipment

and underwater compass to find the spot and search for it,

navigating underwater with compass is super cool and funny

I like when I can combine two hobbies at the same time :-)

 

working with stainless steel is hard and expensive,

I simply suggest you find a thick plastic plate, color and size define how hard it is to find,

drill 1/4 inch holes spaced 1/4 inch, this way you can "draw" the numbers or information

you need to find the final stage.

this kind of plate will last 500 years and is very easy to wipe clean by finders

so they can see the info.