What we’re expecting
The original Galaxy Watch Ultra earned MIL-STD-810H military certification for temperature, altitude, dust, and salt-fog resistance. Samsung hasn't certified the Ultra 2 yet, but the titanium and sapphire build makes a carry-over the safe bet.
Samsung hasn't certified the Galaxy Watch Ultra 2 to MIL-STD-810H, the military standard for drops, extreme temps, and water pressure, but the titanium and sapphire build makes carrying it over from the first Ultra close to a lock. Same materials, so the paperwork probably follows.
How does Galaxy Watch Ultra 2's water resistance compare?
Water resistance rating, higher is tougher.