Introduction: Deep Sea Secret

Hi all,

This is my first instructable so I may not have documented everything to the best of my abilities along the way. But if you get the gist of it, you can really do with it what you want. I thought the secret compartment was a fun prompt for me to get into this community and I think I have a great idea. This is called the deep sea secret because this compartment contains a hidden message! The basic idea is an ancient wooden chest (a block of wood) contains a scroll (a piece of paper that is rolled up tight) with the key to happiness (or just a place to leave messages for you family). Whoever finds this chest, will live a long and joyous life.

First things first!

You'll need a piece of wood. I went down my street to the park and found this log on a trail. Turns out it had some funky designs on it from some beetles that procreate inside the bark. The neat thing was that their designs clued me into the fact that it was elm wood because that is their favorite.

Elm is a sturdy tree and resists water very well. It is hard to carve but great for this fish tank environment!


A sizeable piece of wood

Pennies, nickels

Hot glue gun & non toxic glue

1x Cork


Piece of paper to write your message on

Optional: Lemon Oil

Step 1: Sizing the Wood Down

Once you have selected your wood, you'll want to demarcate the general location of your chest. Mine is about 1.5" all around. I found a pretty square corner to cut the wood down to. You'll need a saw and a table vice grip if the wood is dense and thick. If not you may try to whittle it down with a knife. Just always wear protective gear when necessary.

Step 2: Carving and Drilling; Corking and Polishing

1. Now you have the basic geometric shape that you can work around. To carve, you may need some carving tools. Something like this should work:


should work.

Basically you are looking for a variety of sizes of the chisels to get various level of details. I highly recommend wearing work gloves while chiseling.

I chose a part of the branch that had the interesting alien carvings on the wood from the beetle rather than go my own intensive carving route. But I did carve out some straight lines to give it more of the chest-made-of-planks look.

As you can see in the left photo I am working on another piece of wood -from the same branch- that I want to carve into a canoe with a native on it. Its a bigger task than what I have time left for in the competition, but I should update this post when it is complete. The idea is to attach a fish pole to the man (wire coming from a hole that is glued at the base) that one can loop around the hook that is attached to the treasure chest. That way you don't need to get too wet!

2. Next bit of subtractive work is to drill a hole in the top of the wood. I use a outlet powered DeWalt. This should do fine.

You may choose whichever drill size you would like! It depends on how much of a secret to happiness you think there is! I chose a quarter inch drill bit. Remember to drill carefully lest you make a through hole and the chest leaks.

3. Take any old cork and whittle it down with a knife to fit the dimensions of your hole snugly! This will make your hole airtight!

4. To coat the wood while not harming your fish, use natural ingredients like lemon oil.

Just pour some on a paper towel and rub it on. Let it dry for 5 - 10 minutes. Disclaimer: I think this should work fine, but we shall see in a week! Otherwise there is no need to coat the wood other than aesthetics.

Step 3: Cleaning and Glueing

Since the wood will not sink on its own, I came up with the idea to add a net of coins to it. Before you put coins in your fish tank, clean them very well with some bleach and dry them. Pennies are preferable because they actually prevent algae!

1. Then lay your string out in a crosshatch pattern leaving some space between the strands. I used about 16 pennies and three nickels and glued them on to various parts of the string with hot glue.

2. I also hot glued on a hook of wire that I poked into the cork on either side. That way there is something to grab onto when some one wants to know the secret to being happy.

I used this glue because it is non toxic and should be fine in the tank.

3. Once your net has dried, hot glue it onto your chest!

Step 4: Placing the Secret Compartment

Now that everything is ready, place everything into your tank! The next time you have friends over you can ask them where they think the secret to happiness is? Or when you have grandchildren and your fish are long decayed you'll dare em to stick their hands in the tank to retrieve the message!

- Mine still floats a bit in the water but I like it because my fish can swim underneath it.

Secret Compartment Challenge

Participated in the
Secret Compartment Challenge