Building a truly waterproof geocache

A friend whose family has access to a fairly large pond invited me and a group of friends out for a day of swimming and boating. While out enjoying a lovely Kansas day, I found a spot on the pond — an island — that I thought would make a perfect spot for a geocache. In general I’m a fan of caches that are fun to get to but not super hard to find (no one wants to hike 8 miles and then spend three hours looking under rocks) so this island would be perfect — the cache wouldn’t be too hard to find, but it wouldn’t be a park and grab either.

While a lot of places sell “waterproof” containers, most are built to get splashed, or maybe briefly dunked. But when you’re hiding a geocache in a pond where it could potentially be submerged for months at a time, not to mention frozen in the winter and baked by the sun in the summer, you’ll need a stronger build. I decided to make my cache out of PVC, and I wanted to explain how I went about doing that. I should preface this post by saying that I really have no experience with plumbing in general, so this post is written assuming no expertise, and if you see anything that can be improved let me know.

Parts list

These are just the parts I used, most of them could probably be substituted for similar things — in particular the ginormous tent stakes were only necessary because this cache is going into some pretty deep mud:

Here’s a picture of the parts that went into my geocache (except instead of thread seal tape, I have a small tube of dope in this picture — I ended up returning it and getting some tape before I built the geocache):

Geocache Parts
The parts used to make my geocache

Building the Geocache

Once you have the parts, putting everything together is pretty straightforward. There are really only three steps:

  1. Cut the PVC pipe to a more usable size.  I chose around 8″ because that would give me enough room to store the pencil and Lego guy.
  2. Glue the end cap and the thread adapter onto the pipe.  Being a PVC noob, I found this video pretty helpful. Basically, you…
    1. Apply some primer to both the male and female sides of the joint.
    2. Apply some cement to both sides.
    3. Join the two sides of the joint with a 1/4 turn and hold them together for a few seconds (the video says 5ish, the cement can says 30) so they don’t come apart.
  3. Secure the steel cable to both the pipe and the stakes.
    1. I used a noose knot to secure the cable to the pipe, and made sure it was tight enough that it wouldn’t slip over the the caps. Though the steel cable is kind of tough to work with, its inflexibility helps make it harder to slide over the cap end.
    2. Once you have the knot tied, apply one of the clamps so it can’t come undone — basically you can just clamp it right next to the knot.
    3. I used another noose knot to secure the cable to the stake, although I think the knot choice is probably a lot more flexible here. I was originally planning on tying the knot through the loop at the top of the stake, but if you look closely there are actually small holes just below the top of the stakes, and the cable I had fit perfectly through these so I ran the cable through them instead.
    4. Finally, use the other clamp to secure this second knot.

Once all of this is done, you just need to write / print a “Geocache Note” (see the right-hand column of the Hide & Seek a Geocache page). Since I was using waterproof paper, I hand wrote my note.  Here’s a picture of the trimmed, glued-together cache and note (I should’ve taken this picture after I tied the cable on — sorry that step is not photographed here):

Geocache Build
The geocache after being shortened and glued together

Placing the Geocache

Once everything is built, putting the geocache in the ground is the easy part.  Some friends and I found a nice spot on the side of the island — an 8″ vertical, muddy wall — that wouldn’t get stepped on (whether you were walking on the island or wading through the pond) and wouldn’t interfere with boating. Then all we did was drive in the stakes, wind the geocache around the hooks on their tops (similar to the cord on a vacuum cleaner) and call it good.

Geocache Home
The geocache’s new home

So that’s all there is to it! If you have any questions or feedback, let me know in the comments!

A cache on a peninsula

Today I found a geocache wayyy out on a peninsula on Milford Lake:

A map of where the cache I found was placed
The hike started quite a ways north of the top of this picture

It was a really difficult hike (at times — one commenter described it as “by far the most rigorous cache I’ve found”) but I think it was worth it — the view from the edge of the peninsula (a sandy cliff maybe 20 feet above the water) was incredible, and no one had visited this particular cache in over a year.  For the most part everything went smoothly, except for a branch that broke under my weight.  Fortunately, though, I only fell a couple of feet since I was just trying to cross a fallen tree.

I’ve been doing a lot of very easy caches recently (mostly cemeteries, since they often have a lot of cool history) but I decided today would be a good day to be a little more adventurous.  I’ll probably go back to more tame caches for a while, but it’s definitely nice to know that caches like these are out there.

The geocache's log
The cache’s log, showing no one had been there for over a year
The view from the cache
The view from where the cache was hidden — click for the full version.


The schemer logo
The schemer logo

I recently found myself with some free time in Topeka, after the final appointment for my “subepithelial connective tissue graft” (aka gum graft) got done early.  That whole process is probably worth its own post, but the short version is: some gum tissue had to be moved around in my mouth, and everything went fine (it’s a pretty low-impact procedure).

Anyway, not wanting to drive back immediately (since the drive takes nearly an hour) I decided to explore Topeka.  In the past I would have looked for a nearby or highly-rated geocache, but I didn’t feel like digging around and trying to be sneaky.  Instead, I thought I’d try out schemer.

Schemer, which advertises itself as “The beginning of everything worth doing” is pretty similar to geocaching in spirit: you identify places you want to go / things you want to do, do them, and then mark them as done.  It’s entirely crowd-sourced — that is, the places to go and things to do come from other schemers — and you can go as fast or as slow as you like.  It’s a google project, so it integrates really tightly with google+, and has excellent mobile support.

I chose two schemes to start with — the first, to get a shake at an old-style soda fountain, was foiled when I got there at 4:15 and it closed at 4:00.  The second, to visit the great mural wall of Topeka, was more successful.  The mural itself is pretty neat (you can read more about it / see more pictures on their website) and quite large.  The whole scheming-experience is pretty smooth, too — you pick your scheme, navigate to it, and then check it off your list.

Sure enough, once I got there, there was a geocache at the mural too.  I was able to find it relatively easily, but getting the cache itself was another story — I tried for about 20 minutes (and probably looked pretty shady as I was trying to get at it) but eventually heard a siren and decided that was my cue to leave.

All in all, schemer worked quite well (oddly asymmetric mustache-logo aside), and I had a successful hour and a half of urban exploring.

Part of the great mural wall of Topeka
Part of the great mural wall of Topeka

More Geocaching!

I've been doing quite a bit more geocaching recently. None of the places I went to or things I found were worthy of their own blog post, but a list of them probably is:

  • The smallest geocache ever (watch for scale):
    The smallest geocache ever, with my watch for scale
  • A neat statue from a cemetery:
    A neat statue from a cemetery
  • An interurban railway bridge:
    A bridge from the interurban railway
  • A cool stone bridge:
    An old, cool stone bridge
  • A creek I had to wade through:
    A creek I waded through
  • A geocache placed 10 feet off the ground:
    A geocache way up in a tree
  • A gorgeous sunset:
    A really pretty sunset, viewed from the top of a hill

Until next time!


The first cache I found.So, wanting to get outside (but not get lost, as has happened before) I decided to take up a new hobby called geocaching.  It's explained really well in this short video, but the short version is that geocaching is like a global treasure hunt.  Someone places a container (usually a tupperware-type box) and records its latitude and longitude on  Then, I look up those coordinates, go out to where it's hidden, and find the cache.  It's a pretty cool way to explore areas I wouldn't even know about otherwise.

You're supposed to have someone who is experienced with geocaching go with you on your first trip to show you the ropes, but since I didn't know anybody, I had to wing it.  Luckily, everything was straightforward enough that I was able to get going (though some things, particularly the acronyms everyone uses, were still pretty difficult to understand).  I didn't find anything on my first trip out, but I didn't really know what I was looking for – all of the caches I picked were in walking distance of my house, and thus in the city.  It's hard to look for buried tupperware in front of people without feeling a bit peculiar.

The Saturday after my first trip (March 5th), though, I got a little more serious.  I looked up the most popular nearby caches, selected the ones that were out in the wilderness, and picked the top five from there.  I found three of the five – the others were findable, I think, but I had to cross small rivers to get to them and it was very cold out.  Still, I was hooked.  I had a blast seeing the outdoors, crossing some (smaller) creeks, walking where there weren't paths, and breathing fresh air.  I'm sure I'll write more about geocaching in the future, but until then, enjoy these pictures and if you have any questions let me know!

A waterfall and some rapids.A lovely view from a hill in Kansas.Water rolling over some rocks.