Naut's Q doesn't go throw walls, he also doesn't get rewarded for landing on an enemy champion (unlike thresh, even though thresh' Q go through walls and if the adc flashed you don't hit the tower and pull yourself in the Danger) BUT YOU GET REWARDED FOR HITTING A TERRAIN! YAY!
his E requires him to stop movement for 0.25 seconds (i think) which makes all the difference in the world (this is why you combine Q and E at escapes, nautilus mains know what im talking about)
His W is his ONLY Legit Damage source , that can be easily popped by a maxed skill of any laner.
his kit doesn't give any defensive stats, no damage reduction, no free armor, no increased health reg. which makes him squshie compared to other tanks in this current meta
His R, isn't instant, there's a miliseconds Delay between the moment he hits the anchor to release the ult, and between the time the ult takes to start traveling to the target (No matter the distance between you and enemy) that milisecond could mean life or death, his ult should stun the Target for 1 second AFTER they land, cause currently, it stuns them for 1 second (the same second they're knocked up) but the second take around 0,75 of the time, so they're still stunned when they lane, i was hoping for something like Cho'gath's Q Mechanic, the CC applied AFTER they land.
The CC Chain is Nautilus signature, there's alot of small things that people don't notice it until you play him for a Fair while, and when you die to someone because of those small problem, Riot are refusing to look at those problems, small Delays, CC Within CC that Stops you from having a Smooth Combo, and to top it all, they're still not giving nautilus any "Defensive" passive, which is kind of sad, you would think a man in a Diver suit being, you know, The Tankiesh champion in the league.
that being Said, Nautilus isn't Quite the Duelist, and your performance is solely Dependent on your team, it doesn't matter how good you are, or how much you're ahead over everyone, if you're team is doing bad, then trust me, so you are, and here's why:
1- Nautilus has no actual reliable Damage (we're implying that you're playing jungle Tank) Except for his W, that is also, happen to be a Defensive ability at the same time, he unlike most Tanks don't have a spamable ability, and they're all have long cooldowns due to them having CC, and Trust me a Tank that's using his Basic attacks that aren't supported by his kit will have pretty much a really hard time.
2- Nautilus cannot carry, he isn't a Game changing champion, he isn't a great split pusher, his job is to tank and CC, and start praying your teammates have enough damage to kill them before they kill you.
3- Close to no Mobility, other than his Q that you need to land on Terrains, he has a horrible Base movement speed.
4- Fails against Most if not All junglers in Terms of Dueling without teammates help, now i know nautilus isn't Design to duel, but the enemy doesn't care what are you design for, they will try to kill you and you will have 2 options, either to hit the wind, or see how much can you soak up during a Duel, (hint: you will lose the duel)
5- insane cooldowns. i mentioned this before.
Riot need only to do 1 thing to Fix, or make all of those problems acceptable, Give him his full Duration on his W, even without the shield.
that's my 2 cents...well actually it's more than 2 cents.
been a nautilus main for aslong as i remember, still is.