Flash explains it self, but teleport is for easily getting back in action or for using "the back door." Also, if your team pops ward in their brush its an easy way to gank other lanes which is nautilus specialty as long as your teammates are on the same page

My runes are set up for an AP aggreasive approch. Its strange since both my runes and my masteries dont look like a belongs in a tank build. But I really dont think youll need defence runes and masteries so much since the item choices will make up for it and therefore can make your Nautilus more intimidating with more game play due to cooldowns reductions, mana reg and magic penetration since since this build will be lacking in power in late game

These item are easy explained since this build is not for those who need every kill in sight. Nautilus is the master of cc so you should think of yourself as the teams support. By this standard you will not make fast money due to lacking kills. therefore you start with philosopher stone and heart of gold since thet both provide extra gold income. Later items is to make you an ultimate tanker

You start with titan wrath to shield you from harm. dredge line second to be more intimidating in both hooking you enemy and getting out of harms way, this way the enemy will less likely to storm you. 3rd another titans wrath to counter your enemiies growing power and then go full out on riptide. This means you wont be doing so much untill you get to level 4. so most likely you have to have a few stop to base to restore mana and health and hopefully getting your boots and phil.stone. that is another reason why you have teleport skill to not lose any farming.

4th level: Now you and a partner can surprise your enimies especialy since they probably been underestimated you up till now. now with your boots, placements are key. hit them with dredge line, imidiatly following titans wrath and riptide. this will give your teamate a chance to help and with your slows and immobilize have a very good chance of getting the kill. But dont be eager. you dont have to finish him off on the cost of your own death, so allways analyze the situation.

6th level: Now you are really in the game. keep using the same combos as usual but now they will even more likely not getting away if you follow up with depht charge. Also, you can lead up with depth charge if enemy minions stand between you, if the enemy is on the other side of a wall or near enemy turrent.

From now on you have a chance of going 1 on 1. but since Nautilus strength lies in crowd controll you are better off with allies to help you.

when 5 on 5 team fights occur you will really get a chance to shine. just do as you have been doing up till now and you will be fine, just dont be arrogant. if you get low on health, flash out let them chase you while you team still deal dmg and turn when the enemy flee and start all over.

enjoy ;)

on a side note. You will most likely be the one to initiate team fights making you an unofficial leader in some way. so its alot easier to sync your teams strategies instesd of 5 allied champs that roam their seperate ways getting plucked off one by one.

So Nautilus is not only a CC master. but the glue of the team getting everyone together and therefore be more efficiant as a group ;)