I was recently crossing a lake that is commonly used for swimming and recreation. When I was swimming back to the shore, I was constantly nervous that my bag would be stolen, along with the keys in it. The lake spans several hundred metres, so there would have been opportunities for thieves taking our stuff. Luckily, everything was still in place.

I want to find a way to take the key to my flat and bike with me while swimming without any chance of losing them. I do not need more than the two keys and a towel (the mobile phone will stay at home).

Edit: Thank you all for the overwhelming amount of replies! I try also to follow all the comments and still don't know which of the replies I should pick for marking as the answer because so many of them are so great. :-)

  • 4
    Swimwear often come with small pouches for small objects. Have you not tried this? Is it impractical for you for some reason?
    – Roflo
    Aug 2, 2017 at 14:39
  • 15
    Note that many modern car keys, even without integrated remotes, have electronics in them and may not tolerate immersion.
    – Freiheit
    Aug 3, 2017 at 1:21
  • 5
    Is the bike you're referring to a motorbike, or a bicycle? If it's a bicycle, this is a great example of why a combination lock is better than a lock with a key.
    – Scott
    Aug 3, 2017 at 3:08
  • 3
    related question on Lifehacks.SE (lifehacks.stackexchange.com/questions/7035/…) Aug 3, 2017 at 8:01
  • 4
    If you're swimming in a lake hopefully you have a tow float / buoy - you can always get a dry bag, fill it with bits (an extra air) and clip to that?
    – Aravona
    Aug 3, 2017 at 9:19

15 Answers 15


Lots of swim/board shorts come with key keepers in the pockets. Chances are you may even have one in the swimwear you own. It's simply a length of elastic cord stitched into your pocket. If you don't have one, it can easily be added. You attach your keys to the loop using a girth hitch:

enter image description here

  • 2
    Is that the same as a larks-foot knot? Aug 2, 2017 at 15:24
  • 3
    @TobySpeight Essentially, they are similar in appearance, but the difference is a girth hitch is tied with a closed loop, the Larks-foot (aka Cow Hitch) is tied using the open end of a rope. When securing keys you want it to be to a closed loop so it can't slip off.
    – ShemSeger
    Aug 2, 2017 at 16:54
  • 6
    Lake swimming doesn't always mean this kind of clothing though - many lake swimmers I see are either in wetsuits or speedos... Though if you're wearing these then it's a good option :)
    – Aravona
    Aug 3, 2017 at 11:20
  • 2
    @Aravona my winter wetsuit has a key keeper pounch on the lower the leg. For my summer suit I put the key on a thin rope around my neck and inside the wetsuit.
    – Gusdor
    Aug 4, 2017 at 8:41
  • 2
    @Aravona I get irrationally annoyed when my suit doesn't feature a pocket. Its a killer feature.
    – Gusdor
    Aug 4, 2017 at 8:43

There are a few ways to do this in addition to the previous answer. If you have a car with a hitch:
enter image description here

This is what we use when we SCUBA dive.

Since you are only swimming and presumably not going to great depths, you can also use a waterproof wallet. I have two varieties:

enter image description here


enter image description here

The wallets tend to run less than $10, the hitch lock is more like $30-$50.

  • 4
    In the UK, car insurers do not appreciate the keysafe solution and you may find your insurance invalid if your car is broken into because you stored the car key in a keysafe. It is best to get a spare cut, take it with you and lock the original inside and out of sight.
    – Gusdor
    Aug 4, 2017 at 8:38
  • 1
    Wow! Would this also apply to using the external combination lock? You lock your keys in the car and use the number pad to lock and unlock the car.
    – Pete B.
    Aug 4, 2017 at 9:20
  • 4
    I'd advise against the hitch lock; it's opened pretty easily.
    – SQB
    Aug 4, 2017 at 9:40
  • 1
    SQB, Master brand locks in general are pretty easily opened. There might be some other brand of hitch lock which is more secure. In any case, bikes generally don't have hitches, so it wouldn't solve the OP's problem. Aug 6, 2017 at 18:25

If it's just the keys that need securing, I love key wristbands. They are properly secure and you have the key in sight if you are a bit paranoid about it ;) I prefer it over any kinds of bags on strings, as it gives you less of a hassle and less of a feeling you might lose that stuff dangling from your wrist at any moment.

If you hit your favourite online shop with "key wristband swimming", you should get some. Example:

key wristband

As an alternative for more than just keys, I find running belts with pouches quite helpful. Note that they are typically not waterproof, so if you need to take your smartphone, you will need to protect it separately. Example:

belt pouch


We've has a similar question on Travel.SE. The answer below is largely based on this other answer of mine.

Invest in a Dry Egg/Box

My suggestion is to carry your keys in the water with you when you go for a dip. Keys can easily fit in what is called a freediving dry egg/box which, as the name suggests, is a gadget used by divers to keep their stuff dry whilst in the water. These gadgets come in various different sizes, cost under €20 and look something like this (image courtesy of ScubaStore):

freediving dry egg
(source: watersportswarehouse.co.uk)

I have a dry egg I've been using for five years now. I've taken it with me countless times out in the sea and it has done its job.

Test for Waterproofness

First thing you should do after purchasing your egg is to test ride its watertightness. Put a piece of paper in it, lock it up and throw it in a sink/bucket full of water. Then wiggle it around for a few minutes. Take it out, open it and check the paper: if it's wet you either did not close the egg properly or it leaks.

Wearing Tips

One possible way of carrying the egg whilst swimming could be replacing the lanyard with a longer one so that you can wear it diagonally across one shoulder like a shoulder bag. Other options include tying it to your swimming trunks, wearing it around your waist, your neck, or wearing a rubber weight belt of the type used by freedivers on which you can strap the box. The needed comfort also depends in how much swimming you are planning to do.

  • 2
    +1 for thinking about the risks of hooking up the cord while swimming.
    – Criggie
    Aug 6, 2017 at 18:24

I would be very leary about taking keys out into the water - most car modern car keys are not particular water proof and if you lose it in the water, it's pretty much gone for good.

I use a combination lock box that attaches to my car. Eg something similar to this

enter image description here

This allows you to leave bigger items in the car and rely on the car locks to keep every thing else safe.

  • 3
    Note: for obvious reasons don't use this if your car has a key fob/push to start/unlock. If you have such a car, AFAIK you can remove the actual key form it...take that and use it.
    – BruceWayne
    Aug 3, 2017 at 4:09
  • 18
    Why is everyone assuming car keys when the question says house/bike?
    – Weckar E.
    Aug 3, 2017 at 4:45
  • 3
    This is the perfect answer for a bike too.
    – RedSonja
    Aug 3, 2017 at 6:25
  • 5
    It would be more correct to say that this allows you to rely on the combination lock box to keep your car and your possessions safe. At least unless you get a combination lock box to keep your car key in that is at least as safe as the car.
    – user
    Aug 3, 2017 at 7:18
  • 2
    @MichaelKjörling - that is true. But I suspect most cars are much quicker and easier for a thief to break into than small steel boxes locked under a car =) Aug 3, 2017 at 23:26

As a nudist/naturist, I've been to resorts where I've rented a cabin or trailer and needed to keep the key with me. As the resort(s) deal with people who aren't wearing trunks or have pockets, the key they provided was attached to a coil wristband, much like a telephone receiver cord. I was then able to keep it around my wrist the whole day while swimming, hiking, playing tennis, etc. without concern of losing the key(s).

I've attached a stock photo as not to advertise for anyone; however, these keyrings were under USD $1 or GBP £0.76. Spiral Wrist Coil Key Chain

  • This combines well with the "dry egg" answer if you have an electronic car key, too. Mar 11, 2019 at 16:37

Very low budget solution: Safety pin your key to your swimsuit--inside a pocket if possible.

  • And exactly what you do at swimming pools with your locker key.
    – ShemSeger
    May 12, 2018 at 18:52

You can get waterproof belt pouches. I used to use them when I wore a wetsuit for kayaking (a drysuit makes this simpler). They'll easily hold cash + phone +keys, and are nicer for swimming with than something that trails round your neck. As kayaking sometimes involves swimming in white water with trees and rocks around, the pouches with lanyards would be snag hazards, especially carried round your neck. For short swims with more stuff I've used a small dry bag (the roll top sort).


There is a product that launched in 2015 called PocketBands. It is a low profile silicone band/bracelet that has a hidden pocket. You insert your key on the underside and it stays secure while swimming, running or other activities. It only holds one key, so you would need to buy two for both your keys. I bought these when PocketBands were a Kickstarter project, and the keys do stay put! They are less than $10.


You mentioned being nervous about your bag the keys were in, which reminded me of another successful Kickstarter project for a really nice looking, innovative, theft proof lightweight backpack by Loctote which is made of a slash proof fabric. This was also featured on Shark Tank (a TV show that pitches innovative products to a group of investors). I hope this is helpful! The bag is intended to be locked to a fixed object, so being slash proof is important, as long as the lock holds it's less likely a target.

  • 1
    How would a backpack being slash proof prevent it from being stolen off a beach while its owner is swimming?
    – stannius
    Aug 3, 2017 at 17:24
  • 1
    @stannius Per their website, the bag is intended to be locked to a fixed object: loctote.com - so being slash proof is important, as long as the lock holds it's less likely a target. Of course if you put your slash proof backpack on the ground without locking it securely to a fixed object, then nothing will prevent it from being stolen.
    – Adam Davis
    Aug 4, 2017 at 14:00
  • @AdamDavis I thought the same thing as stannius. You should edit your comment-response in your answer; that makes your answer more useful.
    – Loduwijk
    Sep 28, 2017 at 12:50
  • @Aaron I haven't answered this question (this isn't my answer). You can suggest an edit to the answer by clicking the little edit link on the lower left of the answer. Generally, though, comments are sufficient for this sort of information.
    – Adam Davis
    Sep 28, 2017 at 13:02
  • @AdamDavis It is common on Stack Exchange to consider comments as temporary, and we are technically supposed to treat them as such. I do not disagree that "comments are generally sufficient," but pertinent information like this should be added to the answer itself. I have seen some people mass-delete comments that have not been worked into the answer after some time; not on "Outdoors SE" but on others (this place seems more level-headed in general). Anyway, I will suggest an edit.
    – Loduwijk
    Sep 28, 2017 at 13:42

If your trunks don't have a designated key pouch or you're a female you can tie your keys to the draw string inside your trunks or bikini top. If you have a key fob on your keychain leave it in your car or at home. If your car has a combination lock you can leave your keys in the car.

  • 2
    What if your car keys have an integrated fob and key?
    – MJeffryes
    Aug 2, 2017 at 15:47
  • 2
    @MJeffryes related sister site questions Can valet keys get wet? Aug 2, 2017 at 15:55
  • 3
    My car doesn't have a valet key. And more and more cars have smart keys, which probably shouldn't be immersed.
    – MJeffryes
    Aug 2, 2017 at 15:59
  • 4
    @MJeffryes - If you're a Navy SEAL you would probably swim with the FOB part in your mouth like a badass, Beyond that IDK what to tell you. Aug 2, 2017 at 16:05
  • 5
    Almost all keyfobs and electronic car keys are sealed to at least IP65, which allows shallow immersion. I'd still suggest using a waterproof bag in addition to the built in protection (which may be damaged during battery change, over time, or could malfunction for other reasons). Further, you can generally have a non-electronic key made which will only unlock the doors, but won't start the vehicle or remotely unlock/lock the vehicle. This type of key can be taken swimming without issue, and you can leave your keys secured inside the locked vehicle while swimming.
    – Adam Davis
    Aug 2, 2017 at 16:24

I use 3mm utility cord around my neck. I tie in key with a Girth Hitch. Or tie the key into the necklace. I use a double fisherman on the cord.

  • Keep in mind that 3mm cord is enough to hang/catch/choke you... Aug 6, 2017 at 5:31

It frustrates me that most of the answers are unfortunate variations of "just put the keys into your pocket"

The problem with that suggestion is that most sets of car keys include an electronic component with buttons for remotely interacting with the car.

The only other really viable answer I've seen is the Dry Egg thing, but that isn't entirely convenient.

On short notice what I would suggest is one of two things:

1) put the keys in a condom (and if you're worried about the key bursting the condom, but the keys in a plastic bag first), and then tie the condom.

2) buy a cheap jar of jam (or pasta sauce or something), empty it, wash it in the lake, put the keys in it, and put the lid back on. Now you have a dry key store.


My swim trunks generally came with a tie string in the front to permit them to be securely fastened to my waist. So when I was a kid, my house key was merely tied into the string with the standard knot. I always used the same knot as I did for a shoelace, which is called a "Double Slip Knot." http://lmgtfy.com/?q=Double+Slip+Knot

The key would be tucked into my trunks along with the knot. This location may be a bit uncomfortable due to the convergence of dangling brass with other dangling parts, but it has the distinct advantage of simplicity.

The same thing worked for locker keys. Many swimming pools have lockers for your personal items, and this was one method used to keep the key attached.


Most here have focused on taking the key with you to the lake, with the assumption that you have taken your car. Here is slightly different solution:

My house has an electronic lock with keycode. This might seem extreme/expensive but it is useful for more than just going swimming. If you are not taking your car to the beach/lake then this better than the car key safe option. Going for runs/cycles in clothing without pockets is a great help. You don't have to worry about loosing the key of heavy night at the pub and long trips away. Letting trusted guests in without a key is also very helpful. It has temporary codes so you can set/delete/change this after.

Another similar and less costly solution is to have a combination key safe. This has most of the same advantages but for a slight lack in convenience.

  • 2
    The combination key safes are very common, and not inconvenient at all :) some holiday home companies use them
    – Aravona
    Aug 3, 2017 at 11:05
  • 1
    Yes, The key safes are not uncommon. The electronic locks are less common. The main reason I have one on my front door is that my family run a B&B. We also have a key safe for a barn we rent out. Now that I have used the electronic lock I don't think I will ever go back. It is so very handy!
    – josh
    Aug 3, 2017 at 14:17

Kind of like the key keeper on the swim trunks. Some young girls make a cord like that that goes around your ankle to sell at S. Pacific beach's. They seem to work. Elastic cord.

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