I've had 2 800s, 2 810s and 1 1000 (amongst others) and they've all suffered from water penetration when riding in the rain for long periods. In my experience no Garmin USB port is genuinely waterproof, and they will all die if ridden in the rain for long enough. On Transalp 2017, which was prodigiously squelchy, I managed to see off 2 810s and a 1000.
I've had 2 800s, 2 810s and 1 1000 (amongst others) and they've all suffered from water penetration when riding in the rain for long periods. In my experience no Garmin USB port is genuinely waterproof, and they will all die if ridden in the rain for long enough. On Transalp 2017, which was prodigiously squelchy, I managed to see off 2 810s and a 1000.