Hey guys,
this is my first guide on Mobafire. If you like my build, please comment and help me to improve this guide. English isn´t my mother tongue, so don´t hesitate to correct my grammar :3
Now i want to show you the way I play one of my favourite champs, Nautilus.

Although he has AP Ratio, I prefer to play him Tanky AD, because I noticed that the AP version is quite weak lategame, but I´ll add an AP and a Fulltank Guide soon.
So I tried this and it worked pretty well :D
Have fun and I hope you enjoy this guide.

Once, Nautilus was a sailor commissioned by the Institute of War to explore the uncharted reaches of the Guardian's Sea. This expedition took him deep into unknown waters where he and his crew found a vast section of black oozing liquid that none of the crew could identify. Though their job was to investigate anything new that they found, no man aboard was willing to brave the murk except Nautilus. Only moments after he donned the hulking diver's suit and climbed over the ship's rail, something lurking in the muck grabbed hold of him. He clung to the side of the ship, but the thing below pulled him fiercely, rocking the entire ship. The other sailors grew afraid and made a terrible decision. As he stared and pled for help, they wrenched his grip free of the rail. He tumbled into the ink, grabbing the anchor in futile desperation. Dark tendrils enveloped him and he could do nothing but watch as the dimming outline of his ship faded away. Then everything went black.

When Nautilus awoke, he was something... different. The great iron suit had become a seamless shell around him, concealing whatever awful truth lay inside. All the details of his memory seemed fuzzy and indistinct but one fact remained clear: he was left here, alone in the sunless depths, to die. In his hands he still clutched the anchor that belonged to the men who had condemned him. Having no other purpose, he took this clue and trudged - too heavy to swim or run - in search of answers. He wandered without direction or sense of passing time in what felt like an eternal dream. By the time he stumbled upon the shores of Bilgewater, he could find no traces of the man he was. No house, no family, no life to which he could return. Terrified sailors who'd heard his tale directed Nautilus back to the Institute, but the summoners refused to relinquish the names of the others they commissioned. By then Nautilus had learned about the League of Legends and there he saw an opportunity to discover and punish those responsible for the time and life he lost.

''When consumed by utter darkness, there is nothing left but forward.'' -- Nautilus.

PROS:
+CC
+more CC.. really :D
+Strong Earlygame, even without AP
+Best .. Joke... ever

CONS
- Slooooooow
- Bad Lategame if played AP
- Itembuild is very expensive

I don´t think perfect Runes are that important, if you have your standart Offtank runeset, choose it. The way I prefer to play Nautilus is

Greater Quintessence of Vitality
We want to boost our Titan's Wrath as fast as possible, extra health is quite good

Greater Glyph of Scaling Cooldown Reduction
We have the Randuin's Omen in the Lategame, but CDR early is also nice.
Another option is Greater Glyph of Scaling Magic Resist

Greater Mark of Desolation
There is not room for Armor Pen in our build, so Armor will bite our ***es. These little friends help us dealing damage Lategame.

Greater Seal of Vitality
Again bonus health. We want it.

Staggering Blow
Nautilus’ first basic attack against a target deals bonus physical damage and immobilizes the opponent briefly. Staggering Blow cannot trigger on the same target more than once every 12 seconds.

Cool passive. In teamfights, just run around and hit every champ you can. It´s also pretty nice to Dredge Line and then stunning them and shenanigans.

Dredge Line
Nautilus throws his anchor forward. If he hits an enemy, he'll drag himself to his target and his target to him. If he hits terrain, he'll drag himself to the terrain and the cooldown is reduced.

That skill helps you to move faster and more important: pull enemies in your teams. It doesn´t has to do that much damage, so we max it last.

Titan's Wrath
Nautilus places a shield on himself that absorbs additional damage based on his maximum health. While the shield is active, Nautilus' attacks deal damage over time to units around him.

Maybe this is the best skill you have. In this build it is core. For the time you have it, you deal a lot of bonus damage and damage over time. We take it at lvl1 and max it first.

Riptide
Nautilus slams the ground, causing the earth to ripple out in waves. Each wave deals damage and slows the targets hit. This slow decays over time. Multiple waves that hit the same target deal reduced damage.

This is our second damage skill (early). It deals decent amount of damage and slows all sorounding enemies. We take it at lvl 2 and max it second.

Depth Charge
Nautilus launches a depth charge towards a target that picks up speed as it travels. This charge knocks up all enemies it encounters while traveling and explodes on impact, stunning the target and launching them into the air.

Your awesome ultimate. It´s nice to chase (or finish :>) low HP enemies. In teamfights, try to hit as many enemies as possible.


In the Earlygame, you should get the skills the way you need them. If you get lvl2 and see, that a Dredge Line would help you to get a kill, don´t hesitate to use it.

Our Core offensive Items are
Frozen Mallet
Atma's Impaler
Trinity Force

You will see that the Frozen Mallet works extremly well with Nautilus. The +700 Health fits good to our Titan´s Wrath and the passive gives you even more CC. That will make your enemies cry and increases the chances for an early surrender win.
Trinity Force gives us a lot of benefits. Attack Speed, Movement Speed, Critchance, the awesome Sheen boost etc... You´ll see that you have to get this fast :D
Atma´s is a nice Armor and Damage boost. It fits well to your huge amount of health and gives you more survivablility against the enemie´s AD carries.

Defensive Items:
Mercury's Treads
Randuin's Omen
Banshee's Veil
Force of Nature

You want to be tanky, so get some of this guys. You can decide if you want Banshee´s or FoN first for some magic res. Banshee´s has the nice Health and Mana buff and an 1st class passive, that may help you the get out of a gank savely. I like to buy Banshee's Veil first, finish Randuin's Omen, sell my boots and at least buy Force of Nature, which gains Movement Speed,too. If they have an extremly dangerous AD carry you could also take a Frozen Heart instead of Banshee´s, the CDR is really usefull. But most of the time the standart build with 200 armor is enough.

Situational:

If you beat the s**t out of your enemies or you have another main tank, this thing will help you to increase your damage output. The CDR, armor penetration and the active can be usefull.
Looks strange on Nautilus, but it works!

Like I said above: Get it if you think you need it.

I think this is good on every Nautilus. Take it if the enemies have too much Armor/Magic Penetration.

I´m very busy at the moment, so i couldnt put more work into this guide, but i´m sure I will continue it. It would be nice if you try and comment it :)