Alright Guys, This is THE FUNNEST way to play Nautilus. Alright so, some things to know right off the bat, you are not the tank... You are a melee assassin. Let your team know before you start the game when they are choosing so that your team does have a tank.

Get ready for a wild ride.

Pros
- FUN
- Kills
- Great CC
- Great Ganks
- Good at keeping friends close, and enemies closer

Cons
- Kinda Squishy till you get your warmogs
- Might take some getting used to
- Doesn't have as high DPS/Mobility/Attack speed as other assassins
- U Might get targeted more because of your size

We get cloth armor and 5 health potions at the start for standard jungling.

Items are pretty straight forward, you are looking for attack speed early on because of his passive (holds enemy in place, and does bonus damage depending on level). So Berserker greaves, then trinity force starting with phage to slow the opponent obviously and get some good ganks.
Then go either zeal or sheen, depending on what suits you better at the moment. Remember your still squishy, so get in, get kills, get out. Be very careful.

Next we get a black cleaver. This is our big DPSer item. Still Squishy, but a lot more scary.

Then warmog, this gives us our shield bonus when we use our "W". It also gives us nice HP to be able to take hits in team fights.

The Thornmail can be switched out for force of nature or banshee vail or any other defense item that you see fit for that moment.

Also the Guardian Angel can be switched out for another defensive or offensive armor that you might need. If the team is full of low DPS characters, might as well get a Bloodthirster or Infinity Edge.

First for jungling u want your "W" Titan's Wrath gives a shield and damage over time as AOE. 2nd skill is Riptide, then get Titan's Wrath lvl 2, from there get Dredgeline to start ganking. You want to max out Riptide first then Titan's wrath, then Dredgeline. Raise Depth Charge (ultimate) every time you can.

When you fight or come to gank, what you want idealy, is to give a normal hit first, let your passive root him in place for first hit. Then Riptide, to slow his escape and give some damage, then Titan's wrath is optional at this point, if u need the extra health or want the damage over time it helps some times, if u know u can kill u might just want to save mana for now and skip over it. When he starts to get away you can use dredgeline if you didnt' have to use it for your first hit (if you have phage at this point he can't get away). Then if all else fails and he's escaping use Depth Charge.

Note: Also initiating the engagement with Depth Charge isn't a bad idea either. It will soften them up, allow you to catch up to them, stun them for a short duration, and they can't dodge it once it starts moving towards them.

For depth charge you always want to target the farthest squishy character, because it knocks all enemies airborn between you and the target.