All three watches have Sapphire display protection, an ultra-hard alternative to a toughened glass like Gorilla Glass. But in the test, the Garmin Fenix 7 Sapphire Solar offered the best scratch protection of the lot.
The difference would be hard to perceive without the kind of direct comparative testing undertaken by JerryRigEverything’s Zack Nelson, though. He subjected all three screens to Mohs hardness testing, where tools of increasing hardness are scraped across the surface.
He found that where the tool “caught” the Sapphire of the Samsung Galaxy Watch 5 and Apple Watch Ultra at Mohs hardness level 7, it slid across the Fenix 7 Sapphire Solar smoothly.
Mohs hardness 7 is equivalent to Quartz. Mohs hardness 8 is equivalent to topaz, which is where Sapphire falters in the tests, and all three screens get damaged.
Sapphire itself is rated at 9 on the Moh hardness scale, but can still be damaged by slightly softer tools because of the other factors involved when dragging a tool, with some pressure applied, across its surface.
However, the testing does appear to show the Garmin Fenix 7 Sapphire Solar has the highest grade of scratch protection among the three watches.
It is arguable, though, that the Samsung Galaxy Watch 5 is actually the most notable result here. The watch roughly matches the Watch Ultra for hardness and is the most affordable of the three by some margin, available for $229 from Amazon at the time of writing, while the Fenix 7 Sapphire Solar sits at $799 ($899 at its launch price).