How to Make a 200m Dive Watch for $25

@JakeSea modifies a Casio F91 into a DIY dive watch and sends it 200m down to the bottom of the ocean to see if it can rival the most expensive scuba watches.

Directed and Edited by: Brett Hoffman
Featuring @JakeSea

Marine Outfitters Since 1938

[CCPwillfall]

I love this video no 20 minute vlog bs just 100% quality content

[mikeli]

Somehow, casio really understated their products, it's a lot more robust than they claimed

[julioc.]

funny thing is, most guys who wear diving watches have never dive :(

[Drownedinblood]

Casio proving once again they basically made the perfect functional watch.

[ucheucheuche]

0:28 "Watches that do more than keep time. They keep you ahead of your time" Popular in the 80s, 90s, 00s, 10s, 20s, 30s. TRUTH.

[HGSolberg]

The oil filled watch will take a lot more pressure than 20 bar. Another benefit with this method is that you should be able to operate the buttons under water, without water finding it's way into the watch, something you are not supposed to do, even with the most expensive dive watches.

I do believe it's a good idea to use silicone based oli instead of mineral oil, though, since mineral oils might have small amounts of corrosive components in them, that might harm the watch over time. I also believe mineral oil will yellow over time faster than silicon oil, but not 100% sure about that.

[RafaelCarvalho-rdlc]

My f91w is my go-to watch for surfing for years now and it has never let me down, even when taking 2m waves right in the face it acts like it ain't nothing

[jayp]

I've been snorkeling with my stock F91W multiple times in salt water, and never had a problem with water intrusion or corrosion. Those are shallow depths, but I would say that it's more than just "water resistant". (Also I regularly do things like hose off my arms, take showers with it, dip into buckets of water, etc.) This video is a great idea for deeper depths, and it makes total sense. As long as the mineral oil doesn't eat into the plastic casing or gasket over time.

[JakeSea]

Hi Everyone! Brett and I are very appreciative of all the support on this video. It has been amazing watching it explode in popularity. And while many of you appear to be watch enthusiasts (myself included), those of you here for the boating can still find us on my channel. Brett and I still make content together and would love to see you over there!

We just might drop a few more watches to the bottom 😉

[WyvernDotRed]

The "depth" rating is actually of equivalent pressure and does not include any increase of local pressure due to currents.
So you tested it to a higher standard than what a watch pressure tester would, it's more like the "300M" rating.
But hydro-modded watches are known to be practically infinitely waterproof, though with a bubble the caseback might dent in.
What went wrong with the stock F91-W is that the inner air compressed so much, that the crystal pressed on the LCD and shattered it's glass.

I've hydro-modded a B640M and a GBX-100 myself, with the latter the oil broke the screen, which I repaired with a new polariser.
Another benefit is better viewing angles, especially under water, where the crystal doesn't turn in to a mirror beyond a certain angle.
It is tricky to avoid a bubble from forming in the plastic housing of the module, which might get out over time.
And depending on the used oil it might turn yellow or cause the gaskets to swell, the latter also happened to my GBX-100.

Even still, stock F91-W are known to survive being used on actual dives, as Casio greatly understates their water ratings.
Also, you commented on dive-watches being too expensive, but only mentioned Omega in the end.
Perhaps the cheaper Vostok Amphibia divers, or Chinese imported ones would be interesting too.
Just One More Watch recently showed a 1000M rated diver, though it's gaskets were smaller than a Vostok's and the F91-W's.

[meg]

Ive been using this watch for 3 weeks working 5 -6days washing cars and never had a problem best value for quality!

[cameronj]

Very nice. Bell & Ross used this same science to create the hydro max, which is water resistant to 11, 000 meters, but costs around $2500

[peperiera]

The magical part is that for 10 bucks I’ve been pushing it to the limit with no fear and it’s always responded perfectly. If anything went wrong (for two years it hasn’t) you can learn the lesson and get another one

[chrisp.]

Love my green F91W, it’s my landscaping watch, and I nicknamed it the Master Chief watch.

[alexanderstephenevi]

My f91w is worn daily in the sea, pool, shower, ecc. after 3 years still perfect…

[incargeek]

I think this shows that the buttons are well sealed. If the non-oil watch buttons didnt seal, water would have seeped in to equalize the pressure, and the glass might not have broken. Of course, the electronics might have failed eventually in the salt water but its worth testing a pressure- equalized watch.

[stoundingresults]

Poor Casio on the left sacrificed for science. 😔

[johnstarks]

My issue is what are the long term effects of mineral oil on the internal components, and insulated coating on the pcb.

[fredericcolombier]

Casio are very reliable watches, my father like the Casio, he have plenty of them from the ealy 80's to today, for every day, they all works.
Part of them, on their original Battery .

[Tommm]

Hey thank you for your video this is awesome I've been working around boats for a little while now and everybody tells me to get a watch that's at least 200 m water resistance but I don't really have the money for it and now I have solution to my problem thank you