Thoughts on underwater cache

[+Korichnovui]

Hello,

I live in Tri-Cities, WA, at the confluence of 3 rivers which converge right in the middle of our towns. This river area provides a lot of opportunity for water sports and swimming. I personally enjoy cruising around in my motorboat, doing wake sports, and even just swimming outside the boat and seeing how deep I can dive down into the water. The river is typically 15-25 feet deep but can easily hit > 30 feet or even > 60 feet deep in some spots. So naturally, now that I'm getting into geocaching, I want to make an underwater cache! We don't appear to have a significantly deep one in my area and I think it would be pretty cool, if done right.

Before creating this post, I did a search of the topic, and previous threads didn't really address the questions I have. Those questions are:

1. Do people even like going for underwater caches?

2. Which underwater caches have you seen that were "done right" vs what mistakes have you come across?

3. Which materials may be required? Can rite in the rain paper or other specialized paper remain submerged and stay in good shape? Can you write on it with a pencil - underwater?

4. Are there any safety or liability concerns in this sort of venture?

I'm not talking about caches that are just underwater that "may require wading". I'm thinking 8-12 feet deep, requires diving down, but doesn't require SCUBA.

One idea I saw in a previous thread that seemed pretty good was to have it be a multi-cache where the submerged object simply gives a clue / coordinates for the final cache location. This idea has several merits - don't have to maintain an actual underwater cache container, don't have to deal with a log in/on the water, maintaining the land cache is much easier, etc. The one drawback is, in my mind, the adventurous one though - wouldn't it just be really cool to find and log the cache while underwater?

Edited April 11, 2018 by Korichnovui

[garyo1954]

Death by drowning might be considered a liability.

Visibility would always be a problem.

"Here’s the straight scoop folks:

First of all, when you place objects on the bottom of the ocean, rivers or lakes, you run the very real risk that currents and turbidity will deposit debris and sediments over the top of the object. Of course this is in addition to the host of marine organisms that will grow on any underwater surface, thereby camouflaging the object further and making it very difficult to re-locate even when there is good underwater visibility. What is ‘good’ visibility? Well, in open water that is away from the shore (where turbidity is always higher due to the action of the water near shore) good visibility might be about 50 feet in places offshore around Florida, etc. That’s not to say that I haven’t had better; I have had visibility on dives well in excess of that. However, when it comes to visibility near shore in the ocean, lakes or rivers, ‘good’ visibility may only be 12-20 feet, and average visibility would be less.

Secondly; speaking of visibility, it can vary greatly from day to day. Underwater visibility is a function of how much light is in the sky and the water turbidity (suspended particles). Things like rain and wind as well as plankton/algae blooms can quickly affect water clarity and the visibility. There are times when visibility can be as low as one-foot, and having low visibility is not an uncommon situation… Murphy’s Law comes to mind."

http://www.theprepperjournal.com/2013/11/04/underwater-caches-great-idea-prepping-disaster/

Edited April 11, 2018 by garyo1954
added link

[+cerberus1]

We've found a couple snorkeling hides, on one we were the only ones to find it.  Few went there, one went with scuba for some reason.  I believe the current moved it from GZ, and lack of maintenance got it archived, so maintenance even for a stage is still a consideration.  Most had problems finding them, small containers and pond scum, milfoil, and lily pads.

The caches "done right" weren't when found the COs never asked for permission.  One lake allowed boating but not swimming, so we kinda got the idea permission not only wasn't asked for, but the huge signs weren't even read.

Realize whatever you use will get wet.  Diving slate seems to be the popular thing now.

Caches aren't rated for safety.  The site has a disclaimer, we put it on ours that might need it, but everyone knows they can just pass by your cache.

Seems the same people in my area go to caches over just 2.5 in terrain.  One cacher said they might give up when they realized they were pretty-much putting out caches for four people.   

[garyo1954]

These didn't last, but might give you some ideas of the problems involved.......

GCEE43

GCHPJ9

GCKC4N

GCHZZ7

GCPFQY

GCQD1G

[+J Grouchy]

I have family in Reno, Nevada...so this one always intrigued me. I probably won't ever be able to go for it, though.  It sounds like the log is some sort of slate or board that one signs with a grease pen underwater.  

[+niraD]

The underwater caches I've found have been tethered, so finding the cache required finding the tether line and pulling the container up.

Even with a watertight container, if water got into the container while the previous finder retrieved, opened, closed, and replaced it, then the contents are going to be wet; a watertight container will keep water in as well as keep water out.

Even with a watertight container, if something like a plastic bag gets caught in the seal, water will wick into the container.

Some people use a container within a container. That helps if the outer container leaks, but not if someone with wet hands signs the log.

A design for an underwater cache that I've seen, but which I haven't actually seen used in the wild, is to use an outer container of PVC pipe with a cap glued to one end and a stopcock-style valve glued on the other end. The pipe is tethered to a weight so it sits underwater with the cap up and the valve down. Inside the pipe is a watertight container like a preform with a good cap with a gasket. Finders take the pipe to the surface, open the valve, slide out the inner container, open the inner container, sign the log, and put everything back. The inner container keeps the log dry (or close enough to dry). The air trapped in the pipe keeps standing water away from the inner container. Anyway, this design sounds good, but as I said, I haven't seen it actually used in real life.

Another approach is to just assume everything is going to get wet. For example, the log could be a dive slate inside an ammo can that has holes drilled into it so it won't trap air inside.

[+DragonsWest]

Ponds, lakes, bays have some issues, but...

Rivers are going to have flow and siltation problems whenever there is snow melt or rains.  Visibility in many rivers can also be low due to algae, which prospers with ag runoff.

[+cerberus1]

1 hour ago, niraD said:

Another approach is to just assume everything is going to get wet. For example, the log could be a dive slate inside an ammo can that has holes drilled into it so it won't trap air inside.

Yep.  There's a regular here in the forums who says that's what they've used. 

[+coachstahly]

I have a 5/5 multi that's on a lake (mostly its backwaters), but the ones submerged don't require anyone to swim.  One of the stages is a partial diving slate that stays underwater, except when found, and is tethered to its location via a metal fishing lead wire.  I check on it twice a year and use a sharpie to refresh the coordinates.  Another stage is also tethered but sits on the bottom.  I have a series of metal fishing leads connected to a nalgene water bottle that's weighted down with rocks and sand and on the top of the weighted items, I have a diabetes test strip container with the coordinates for the next stage.  It's not been wet every time I've checked it.  The last submerged stage is an aluminum dog tag that has the coordinates stamped onto it.  It's secured with (you guessed it) a metal fishing lead wire on the underside of an old tree stump that's been there for years.  With the exception of algae, it rarely needs any attention.  There are 2 SCUBA caches within 50 miles of my home coordinates, but they haven't been found in years.  One is a multi (final on land), while the other has a slate (I think) attached to an old bus that sits at the bottom of an old quarry and is an area that's used for certification.

If it's the river that you'd be using, the current and the visibility would certainly be an issue.  I'd be inclined to tether it to something to make sure it doesn't end up floating away with the current.

[+Goldenwattle]

On 4/12/2018 at 3:04 AM, niraD said:

The underwater caches I've found have been tethered, so finding the cache required finding the tether line and pulling the container up.

That's like the ones I have found. I swam out to one (it was tethered to a post in a lake), but it was very difficult trying to tread water, as the current tried to drag me away while I signed the log. I dropped the cache and down it went. Luckily I didn't drop the log. I swam back to shore with the log and returned a few days later with a replacement cache. Good idea, caches in the water, but problematic.

[+OwenfromKC]

I think this is what you are envisioning.   It is in an urban lake.  Cache page describes it well and pictures show what it looks like and about how far it is from shore. It has stood the test of time.

https://www.geocaching.com/geocache/GCXW6H_oh-carp

[+Meredith66]

I live in Lake County Florida if we don't have the ocean we have the Lakes that are very dirty and I don't like it at all I won't even try to find them if they're not filled with algae and other gross stuff it's filled with all types of bacteria I really wish they wouldn't have this... Besides putting in The Lakes over here is really dangerous I don't want to get eaten by a crocodile  or a gator ??

[+ScooterDawg]

Here's another one to look at for ideas: 

 

https://www.geocaching.com/geocache/GC2582G_pencils-only

 

[+rb9228]

I hid three scuba diving caches here in Okinawa.

 

On 4/12/2018 at 12:47 AM, Korichnovui said:

1. Do people even like going for underwater caches? Many dive instructors took their students to one of the caches and everyone wrote their names on the log (waterproof notebook, basically a notebook with plastic pages) but very few created a gc account and logged online.

 

2. Which underwater caches have you seen that were "done right" vs what mistakes have you come across? Shortly after I created the three underwater caches, someone placed another at a very popular dive site. They tethered it to hard coral at a swim through. So I really don't have any other caches to compare

 

3. Which materials may be required? Can rite in the rain paper or other specialized paper remain submerged and stay in good shape? Can you write on it with a pencil - underwater? A divers slate works very well. I included a slate pencil inside the container as well. I also placed diver weights to keep the container from floating. I drilled holes into the container so there wouldn't be any air pockets. I also noted in the cache description about not taking it up to the surface (also all the caches were tied off to something)

 

4. Are there any safety or liability concerns in this sort of venture? Well, they were T5 caches and I also noted in the cache page that finders had to be scuba certified in bold font.

3

 

[+badger10]

My son and I put a cache in the Columbia River at Columbia Park (We have met you...we are on the geocoin challenge committee for the Tri-Cities). It was about two to three feet down near the Edison St boat launch in Columbia Park. It was muggled three times and one time they emptied the cache on the bank and took the container. We would be happy to help you put one out.

[+Korichnovui]

14 hours ago, badger10 said:

My son and I put a cache in the Columbia River at Columbia Park (We have met you...we are on the geocoin challenge committee for the Tri-Cities). It was about two to three feet down near the Edison St boat launch in Columbia Park. It was muggled three times and one time they emptied the cache on the bank and took the container. We would be happy to help you put one out.

 

That's cool!

 

I've definitely put this idea on the back burner for now, for a variety of reasons. Popularity, risk, logistical issues, etc.

 

That said, I ran into my SCUBA friend a few days ago, and he asked me, "When are you going to make that underwater cache??" He was pretty excited to help set it up. He's not even a geocacher. But he is a SCUBA instructor and has arranged underwater navigational courses, etc, in the past. So I got some good ideas from him. He feels confident that, if done properly, a physical item put in the Columbia could remain stationary. The big problem will be algae growth. Whatever is down there is basically going to turn to slime, and quickly.

 

If I were to make one of these, my idea would be a multicache where there is an underwater stage that gives information for the final. In other words, I'm shying away from putting the actual cache underwater at this time. My setup would be a large concrete block with metal ring (I happen to already have one of these on my property lol), with metal cable attached, with a number of washers on the metal cable, with a PVC tube to provide buoyancy to make it a little more conspicuous underwater. The information is conveyed in the # of washers on the metal cable.

 

I would love to collaborate with you on this project! I'll send you a private message with more details of what I've thought out.