Apple Watch Series 10 Slims Down, Apple Watch Ultra 2 Gains Black Finish

cafeface · September 10, 2024, 1:28pm

Improved display, faster charging, and sleep apnea detection would motivate me to consider upgrading from my Series 7, but not until pulse oximetry is available for the Series 10.

Shamino · September 10, 2024, 2:15pm

I didn’t say otherwise. I said that snorkeling is shallow water activity. You’re almost always just below the surface, except when briefly diving down to look at or pick up something.

Neither I nor Apple’s video said that people snorkel down to 6m, nor did anyone say that 6m is shallow-water activity. They did say that the automatic depth gauge, which they said can be used while snorkeling, is good for up to 6m. Which I think is completely fair, since it is highly unlikely that anybody snorkeling will go down more than 2-3m, and when they do it will be only for very short periods of time.

romad · September 10, 2024, 2:33pm

Ah, it wasn’t clear on the video. That is cool repurposing already installed sensors for new/additional uses.

ddmiller · September 10, 2024, 2:55pm

I don’t want to get into what is and what is not snorkeling. So just to clarify my point, what I am saying is that the water resistance that Apple is stating for the Series 10 is subtly different from all of the non-Ultra watches that preceded it, despite many of them also being 50m designation. Through the Series 9 Apple never supported the use of Series watches as deep at 6m. The Series 10, however, is the first non-Ultra watch that Apple says is suitable for snorkeling as deep as 6m, and they included the Depth app and water temperature reporting from the Ultra and Ultra 2 for the first time in a Series watch.

This was the water resistance footnote text for Series 9:

Apple Watch Series 9 has a water resistance rating of 50 meters under ISO standard 22810:2010. This means that it may be used for shallow-water activities like swimming in a pool or ocean. However, Apple Watch Series 9 should not be used for scuba diving, waterskiing, or other activities involving high-velocity water or submersion below shallow depth. Water resistance is not a permanent condition and can diminish over time.

This is the water resistance footnote text for Series 10:

Apple Watch SE and Apple Watch Series 10 have a water resistance rating of 50 meters under ISO standard 22810:2010 and may be used for shallow-water activities like swimming in a pool or ocean. Series 10 can also be used for snorkeling to 6 meters. They should not be used for scuba diving, waterskiing, or other activities involving high-velocity water or submersion below shallow depth.

Note that the Watch SE, which has the same water resistance text as the Series 9 had, is not designated for use up to 6m depth - the Series 10 is called out specifically from the SE.

Shamino · September 10, 2024, 4:29pm

TL;DR: ISO depth ratings are not what you may think. A watch that says it is rated to 50m should not be submerged at anything close to 50m.

The confusion here is that the “50m” rating does not mean it can be submerged to a depth of 50m for an extended period of time. It refers to the maximum amount of pressure used during testing under specific lab conditions.

ISO 2281 is the standard for “water resistant”. These are not considered “waterproof” and can only survive limited amounts of time at various depths. ISO 6425 is the standard for so-called “divers’ watches”, which are designed to withstand extended periods of submersion at various depths. ISO 6425 has additional tests for mixed-gas diving.

You’d need to get the ISO standards (sadly, behind expensive paywalls) for the specific set of tests, but one article I found describes how to perform a basic test (for the purpose of repairing a 50m waterproof watch), and it’s not what I would have guessed:

Get a pressure chamber. Half-fill it with water.
Suspend the watch in the air portion of the chamber
Pressurize the chamber to 5 atmospheres (50m)
Check to see that the pressure inside the watch remains 1atm (I’m not sure how you measure this if the watch is properly sealed)
Submerge the watch in the water.
Slowly reduce the pressure back to 1atm
Make sure no air is seen escaping from the watch (no bubbles)

This test is designed so that if the seals failed, water won’t enter the watch, because the air pressure inside the watch will be greater than or equal to the water pressure.

Of course, the ISO test procedures will be more extensive than this.

In terms of what these numbers mean in real life, I found a few articles that say (more or less) the same thing, and also aligns with what Apple said:

“30m” water resistance is 3 atm. This is splash/rain resistant, but generally should be kept away from water as much as possible.
“50m” water resistance is 5 atm. Suitable for showering, bathing, shallow-water swimming, snorkeling, etc. Some say this is only suitable for occasional swimming, not for frequent swim sessions.
“100m” water resistance is 10 atm. Suitable for recreational surfing, swimming, snorkeling, sailing and water sports. Should not be submerged deeper than 1m. Not suitable for diving.
“200m” water resistance is 20 atm. Suitable for professional marine activity, surface water sports and skin diving. Should be suitable for up to about 40m submerging, but you may want to get an actual diving watch if you plan on wearing it while diving.

Watches labeled as “Divers’” with a depth usually means they are certified according to ISO 6425 instead of ISO 2821:

“Divers’ 100m” is the minimum ISO standard for scuba diving at depths not suitable for saturation diving. Typically found on older diving watches.
“Divers’ 200m” or “Divers’ 300m” is suitable for scuba diving at depths not suitable for saturation diving. Typical for modern divers’ watches.
“Divers’ 300+ m for mixed-gas diving” is suitable for saturation diving. And will have special markings to indicate this, along with the actual depth limit.

Additionally:

Water resistance doesn’t mean you should shower with it. Heat, steam and soaps are not part of the testing and may degrade the seals and allow moisture ingress.
Don’t operate any controls while submerged unless the manufacturer explicitly says you can. Pushing buttons and crowns while submerged is not part of the testing and can allow water ingress.
Leather straps can be ruined by submersion.

WRT what Apple wrote:

Both the 9, 10 and SE have an ISO 22810:2010 rating of 50m. According to ISO, this standard supersedes 2218:1990 (to which the Wikipedia article refers). I assume they updated the procedure, but I don’t know what the practical difference is for a customer seeing the result printed on a watch’s face.
This is a water resistance standard, not a waterproof standard.
Apple is explicitly saying that the series 10 can withstand submersion at up to 6m, which is beyond the requirements of an ISO 22810 50m rating and is probably beyond some aspects of a 100m rating

I also find it interesting that Apple documents that none of their watches are rated according to ISO 6425 (for divers’ watches).

Even the Ultra, which they say can be submerged at up to 40m, is only ISO 22810 100m certified - it’s unclear why they are making this claim but did not certify it to 200m, which (according to what I read) would be the minimum rating for diving to 40m.