Dog is order Carnivora. Their digestive system differs from let's say a pig or a human. Dogs can survive without meat (unless cats, that's right) but they cannot strive without it.

That's actually not true. There are dogs with allergies or dogs that are not allowed to consume animal protein (for a short time) for medical reasons. This food is specifically made for them.

Vegans feeding their dogs this food is animal abuse, though. Don't do that, they're carnivores!

If you keep measuring that stuff you can factor that in. But it's not that much of a difference honestly. I mean not like double or half the actual depth.

I don't know for submarines but I've nearly crashed a scientific device because the sonar gave the false depth on our research vessel.

You have to set the sonar to a certain depth which you get from nautical charts. I don't remember the exact value but let's say that the digital nautical chart said 2000 m so the sonar was set to let's say 1500-2500 m. We deployed our oceanographic device when one of the officers double checked with an old nautical chart on paper and it said 1000 m. We've already been down for a few hundred meters when he called us to stop. We then slowly advanced and, believe it or not, the old chart was right. It was unlucky that the real depth was exactly half of what we initially thought it would be. Because of reflection the sonar gave us the way to the bottom and back to the surface as depth. If the officer hadn't listened to his gut feeling we would have wrecked equipment worth more than a big family house. That was off the beaten track though, far away from shipping routes - I think they should be mapped accurately by now. If the setting is correct, sonar gives you a good idea of what is down below. More detailed than satellites ever could.

But as I said no idea how that works with submarines. Maybe they didn't have the sonar on for some tactical or training reasons.

There are still seamounts we haven't discovered yet. For instance, in 2005 the USS San Francisco collided with one which caused serious damage. They nearly didn't make it. Google it, there are impressive pictures of the submarine.

Edit: I just googled the most recent collision with a seamount. That was the USS Connecticut last year.