Waterproof Key Bag for Diving

[lexvil]

Maybe listen more and defend less.

 

[Marlene996]

Progress comes from discussion.

 

[tursiops]

I just did a simple pressure check on the fobs from two different cars. One engages at 600g pressure, the other at 1400g pressure so there is also quite a bit of variety in how much pressure causes it to engage.

When you press the button, there is a spring exerting pressure back. It is that spring that prevents the fob from turning on when the key is under pressure.

If what @tursiops suggests is true, then putting a hard cover over the key buttons wouldn't help as the general pressure would cause the buttons to compress. But again if there is air inside the bag and the air is exerting equal pressure on both sides of the button then the button would not engage as long as nothing externally pushed on it.

The purpose of the hard cover (e.g. the Keebunga and the DryFob) is twofold: yes, it keeps the water out; and it also keeps the pressure inside the case at nearly 1 atm. So there is no extra pressure on the fob buttons. If the key is in a soft case, then it is dry (good) but the pressure inside is equal to ambient. It is the soft case itself that can press against the fob button, not the air pressure per se. at 40m, recrational depth max, the ambinet pressure is 5 atm, or about 73 psi, or over 33,000 grams per sq in. How mig is the key bob button? Even if 1/8 in square, that is over 500g pressure. that doesn't give much margin for you 600g button...and i expect if you test a numbe of key fobs you'd find a lot of variance is spring forces.

 

[JohnN]

I hope this is in the right place and if not please let me know where to move it!

A little over a year ago I started making a simple new product for surfers to put their electronic key fob in and take in the water (instead of hiding in the sand or somewhere equally as sketchy). At Surf Expo last September I had a lot of interest from Dive shops in Florida and the Virgin Islands expressing frustration with the tube shaped products failing and looking for an alternative. Until then I had not considered it for divers as I was diving from a boat and didn't need to take my key.

Since then we have sent The Surf Bag on repeated dives between 12 and 30 meters and have had no failures. If you are familiar with Kewalos Harbor and the Sea Tiger wreck just off Waikiki, this area was our playground.

The Surf Bag (patent pending) is a small waterproof pocket made from retired airline life vests. It has a marine grade steel grommet at one end and uses a TruZip locking zip. It was designed to fit flat the pocket of most if not all board shorts, so it will easily hold a credit card, ID card, paper fishing license, and large electronic key FOB.

A bit of history on the material, life vests are stored in air tight plastic under your seat on the airplane for 5-10 years. What expires on these is the inflater canister and the chemical that activates the shoulder light when wet. It is cheaper to buy a whole new life vest than replaced these two components so the vests were disposed of... until now!

I designed The Surf Bag in Hawaii and it is manufactured in California (and soon also Washington State).

Now that I am confident that this product can is secure enough for scuba diving (to 30m) I'm ready to promote it in the dive world, starting here. I've also become a proud Scuba Board Sponsor as of today!

If you would like to learn more about my product, please ask questions here or visit my website: www.thesurfbag.com
If you would like to buy one please use this discount code for 15% off: ScubaBoard15

If you are in Hawaii, you can also find The Surf Bag at Abundant Life Natural Foods in Hilo and HIC in Kona, HIC on Maui, and on Oahu in HIC, Downing Surf, Wikiki Sand Bar in the Waikiki Beach Marriot and other locations you can see on our website.

I'd really love any questions, tips, feedback etc!
Also if you are on Oahu in April and would be interested in making videos and photos of the bag while diving please DM me. They found my PFO a year ago and I am still stuck waiting for approval for my closure.

I just placed an order.

 

[lowwall]

But again if there is air inside the bag and the air is exerting equal pressure on both sides of the button then the button would not engage as long as nothing externally pushed on it.

Any air inside the bag is at approximately 1 atmosphere (atm or bar or kg/cm2) of pressure. Zip the bag and start to descend. At 10m the absolute pressure is now 2atm. You subtract the 1 atm that was inside your bag and the net pressure on the bag and its contents is 1atm. That pressure will continue to increase 1atm for every 10m you descend. There's really no way around this for a sealed soft case. I just looked at my key fob and the buttons are 1.8 cm2. At 30m, the pressure on each of those buttons will 5.4 kg.

Because people are mostly solid and thus largely unaffected by pressure changes (the exception being our sinuses and lungs), it's hard for us to intuitively grasp the force of even small pressure changes if the surface area is large enough.

I used to be a lifeguard, but my first save was actually at a party where someone tried to run across a floating pool cover. He only got maybe 3m in before it got too difficult to take a step and he stopped. He kept upright and his legs sunk below the surface surrounded by the plastic. He was less than a meter below the surface before the pressure difference was enough his legs were pinned in place. He kept sinking and was starting to panic as his torso went under making it difficult to breathe. To free him, I had to jump in and start at the edge of the cover to sink it and then make a path to him sinking the cover as I went.

 

[Marlene996]

@JohnN Thank you!!

@lowwall Thanks for the share. I'm going to put a disclaimer on it regarding key fobs until when and if I can find a solution to protect the buttons.

I really appreciate everyone's input!

 

[happy-diver]

Just like the centre aisle in Aldi if you did not go in with the idea of buying it you don't need it
But if you did go in to buy the surf sack you might find it in the the regulator dust cap section

 

[ftnpenlvr]

Just placed an order for 2 “bad stamp” bags. I have a DJI Mic 2 transmitter that syncs up to my action cam. i have found that, if i place it against my chest, it records just fine, but, waterproofing it to depth while still maintaining usability has been something i have been scratching my head over. The buttons are on the sides, so not much concern there. the mic itself is about half the size of a pack of dental floss.

 

[Jaan]

I’m still thinking about one for carrying some chocolate chip cookies Loved that story. Haha

 

[Marlene996]

Just placed an order for 2 “bad stamp” bags. I have a DJI Mic 2 transmitter that syncs up to my action cam. i have found that, if i place it against my chest, it records just fine, but, waterproofing it to depth while still maintaining usability has been something i have been scratching my head over. The buttons are on the sides, so not much concern there. the mic itself is about half the size of a pack of dental floss.

Thanks for the purchase! I'm really curious how the recording is through the bag, please update us when you get a chance to use it!