+RenMin Posted May 12, 2015 Share Posted May 12, 2015 Thinking about an underwater cache. A container that would sit on a sunken island in a lake. Maybe four feet deep. An idea I saw involves concrete in a container with a smaller one wedged in. My question is, what have people seen or made that works well underwater? Quote Link to comment
+wmpastor Posted May 12, 2015 Share Posted May 12, 2015 Thinking about an underwater cache. A container that would sit on a sunken island in a lake. Maybe four feet deep. An idea I saw involves concrete in a container with a smaller one wedged in. My question is, what have people seen or made that works well underwater? When this came up before, people said it's tough to keep a container dry, so you need a log that can handle being submerged in water. Quote Link to comment
+niraD Posted May 12, 2015 Share Posted May 12, 2015 I've seen an ammo can work well underwater when the seal is in good condition. I've also seen the same ammo can fail miserably when someone caught a plastic bag between the lid and the lip of the ammo can when closing it; the plastic bag wicks moisture into the ammo can, no matter how good the seal might be without the plastic. I've seen various double container designs that I think would work well, if they were replaced correctly by those who find them. One example uses PVC pipe for the outer container, with a cap at the top end and a ball valve at the bottom end. The ball valve is big enough for a preform to fit inside. When the cache is anchored in place, the air pressure inside the PVC pipe keeps water out even if the ball valve isn't completely closed. And if the preform is oriented with the cap up, then its unlikely that the water would reach the cap. So even if both the ball valve and the preform cap leak, the contents of the preform shouldn't get soaked. Another approach is to give up trying to keep the cache contents dry. Drill holes in the container so water can flow in and out freely, an use a waterproof log, such as a diver's slate. Quote Link to comment
+Oxford Stone Posted May 13, 2015 Share Posted May 13, 2015 One near me is one of those aluminium drinking bottles with a ring-shaped screwtop lid. Chain attached to lid and (as above) to a bucket full of concrete. Dependent upon people closing the lid properly of course... Quote Link to comment
+narcissa Posted May 13, 2015 Share Posted May 13, 2015 The best one I saw was some sort of pipe fitting with a smaller watertight container inside. It had a bit of moisture but it was in pretty good shape for being submerged in ten feet of water. Quote Link to comment
unlimitedtazmania Posted May 14, 2015 Share Posted May 14, 2015 (edited) interesting idea. Edited May 14, 2015 by unlimitedtazmania Quote Link to comment
+cerberus1 Posted May 15, 2015 Share Posted May 15, 2015 (edited) Every underwater container we've found had water in it. Most were FTFs. We have a paddle-to cache (dry land to access), and the ammo can container was submerged 4' for about six months during a flood of the area. After wiping the container and drying my hands before opening, everything inside was still bone dry. - We can't get cachers to use umbrellas to keep containers dry in rain, what do you think they'd do for an underwater one? Like niraD said earlier, a Reviewer posted here once, saying he used an ammo can with holes drilled through it, with a divers slate as the log. I thought it was a good idea. Edited May 15, 2015 by cerberus1 Quote Link to comment
+barefootjeff Posted May 16, 2015 Share Posted May 16, 2015 Thinking outside the square, how about making it a two-stage multi, with the coordinates of the dry-land final written (or engraved) on the underwater object. Quote Link to comment
+cerberus1 Posted May 16, 2015 Share Posted May 16, 2015 Thinking outside the square, how about making it a two-stage multi, with the coordinates of the dry-land final written (or engraved) on the underwater object. +1 We did one (only a few found it) that was a rusted, thick steel plate with coords to the next stage plasma-cut through it. Just laying in a foot of water in a creek, with other similar old bridge parts. Evil. Quote Link to comment
+BBWolf+3Pigs Posted May 18, 2015 Share Posted May 18, 2015 Use a soda bottle preform, with a wire tether, attached to a suitable weight (brick, concrete block etc.) If it tethered such that the opening is kept facign down, water leakage should not be a problem. I have used preform for several underwater caches with no issue. You could use rite-rain paper for extra safety. Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.