Now this guide is my first, so some feed back would be nice.

I am a heavy tank player and must say that in my opinion that Nautilus does have the potential to be another great tank like Alistar the king of cc. The ammount of damage you can take and dish out the name Foreveralone becomes very clear. Since either you will have to be focused down and die while your team takes free kills like their own sale or your left standing over a field of corpses as the enemie scurry away.

Warden's mail
Now some of you may have seen the warden's mail and thought 'wtf?'. Well don't be worried their is reason for the madness, mainly dealing with persistant use of melee dpsers in Dominion. At the very start of the game this will make you a beast if used correctly with Titan's Wrath.

Nautilus' base stats mean then with this one item his physical defences will be almost a 100 and the passive slow on being attacked will usual proc more then you realise. So when taking top tower and you have a Jax or Wukong jump on your face thinking your going to be esier to take down then you actually are. Oh but whast this, now their in your team, slowed and usually stunned with Nautilus' passive to the spot. In other words dead meat and usually you can bait more then one of the enemie to make this mistake. Thus there is your top tower in the bag and a good bit of gold if your team knows what it is doing.

Treads
Now why rush your Treads? "ell there is always going to be cc involved somewhere and you don't want to be stuck in a pack of enemies stunned, while you should be rooting them for your team.

Hexdrinker
With this item I bet some of you have nevereven noticed it was there, but its a fun little item that will save you more then once in the game. Not only does it keep your auto attack high enough that people will not want to get hit but also adds resist which should push that state over the 100 as well by the time you can affort it.

Now these last few items are really for late game and can be changed up depending on what you need nas a team. I go for sheen because its good for after landing Dredge Line in both that it adds ap damage to the skill and then stacks with your passive first hit damage bonus. Gunblade is also their to keep your skills having impact enough to make you a threat not just for your cc. Also if fighting a champ in the middle of his minion wave the spell vamp you get form setting off Riptide can give you a surpising ammount of health.