Apple says that owners of Apple Watch Ultra smartwatches can now have them checked to ensure that they are as depth and water-resistant as they should be.

The news comes after Apple uploaded a support document to its website that details what the test can do and why people might want to request that it be carried out.

"If you have Apple Watch Ultra and want to check that its depth gauge and seals are working properly, you can get a Depth and Water Seal Test from Apple," the page, spotted by MacRumors, reads. It goes on to say that there are a couple of scenarios in which a user might wish to have their Apple Watch Ultra checked out.

• You'd like to check the functionality of the depth gauge in your Apple Watch Ultra.
• You might have caused unseen damage to your Apple Watch Ultra — for example, by crashing while bicycling, or hitting your watch on a rock during a hike.

However, Apple does warn users that an Apple Watch Ultra shouldn't be dived with if there are visible cracks on the display or back crystal. Such cracks can let water in, which is obviously bad. Especially if you're diving under any kind of pressure.

Apple says that "if your Apple Watch Ultra has unseen damage, the Depth and Water Seal Test may leave the watch inoperable and may result in a replacement fee if the device is not covered by the Limited Warranty, or by any applicable consumer protection laws or regulations." However, there is no mention of whether the actual test will incur a fee or not.

Those who want to get their Apple Watch Ultra checked out can reach out to Apple via the usual support channels. Any watch sent to Apple should be returned, or replaced if needed, within ten days.

The Apple Watch Ultra is of course Apple's most rugged wearable and is even advertised as being used as a replacement for a dedicated dive computer.