I'd just parrot what everybody else said but instead I'll give you a few tips for dealing with Naut Top.
A) MR kills Naut. People see Naut and think "CC Tank" not "DoT CC Tank", so the most they ever get is MAYBE Merc Treads. But MR kills Naut's DPS similar to how hard to hurts Singed's.
B) Don't run away from his Riptide. A good Naut Top will use his Riptide while he walks away. The bread and butter of trading with Naut is the Q > AA > W > AA > Walk Out > E combo. Generally speaking your first instinct will be to walk away from the shielded tank once the root wears off but that'll just cause you to get hit by 2 or 3 Riptides. Instead just walk towards him for a brief period and you'll only get hit once, unless the junglers nearby this shouldn't lead you into any further danger.
Should be noted subsequent hits of Riptide deal 50% damage from the initial hit. So getting hit by 1 would say do 100 damage, but being dumb and walking along the Riptide will potentially deal 200 damage (not to mention that slow). At 100 damage that's no big deal but the base damage and scaling is pretty heavy for what it is. My usual rush of RoA + Liandries/Abyssal Scepter will easily be doing ~500 damage for all 3 hits if I'm even in lane.
So when dueling Naut, try and stay on top of him, it's very counter productive compared to most champions but it hits him pretty hard. His Ult won't go through your team, his root won't mean as much since you'll still be able to AA, hook ends up being a minor disturbance. TL;DR, Naut has personal space issues. Sometimes he wants to be sitting on you, sometimes he's a little tsundere and wants to keep distance and close that distance at his pace.
I honestly wish more people laned with Nautilus. It's a really good pick if you want to shut down melee carries early and allow your team to snowball without fear, then transition into a full tank frontline when you're no longer able to duel, short of going full AP, as silly as it is it's pretty useless lategame.
