This is just an information guide for anyone looking to play, it is not an actual guide. This will simply give the stats I can figure out. Please tell me if there is something important I am missing. The guides are not for the actual champions but for Nautilus.

EDIT: Look at Jarvan's build to see how to build him. This will give you immense ganking potential with the extra movespeed and give 40% CDR to lower his sheild cooldown to 10.8 seconds which will almost allow you to keep up the shield at all times.

I made large changes after reading stonewalls impression that helped to increase his potential IMO. I also added a runes and masteries section and an items section.

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EDIT: Stonewall's first impression: http://rog.clgaming.net/blogs/stonewalls-jungle/5599-first-impressions-of-nautilus

Seriously, check out stonewall, he has a LOT of good information.

Passive: 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.

Immobilize Duration: .5/.75/1
Bonus Damage: 8/14/20/26/32/38/44/50/56/62/68/74/80/86/92/98/104/110

This ability is similar to Jarvan's passive only it immobilizes them when it hits and does a flat amount of damage rather than a percent. Immobilze duration increases .25/6 lvl (1/7/13) and Bonus Damage increases by 6/lvl.

Q: 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.

Damage: 80/120/160/200/240
Mana Cost: 60/70/80/90/100
Cooldown: 14/13/12/11/10
Cooldown reduction if used on Terrain: 50%
Scaling off AP: 75%
Range of starting platform for Dominion

Similar to Amumu's Q, it also can be used to pull him to terrain. It will pull you towards a minion if you hit one so be careful with that. This is the very reason that it is comparible to Amumu rather than Sejuani.

W: 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.

Shield Amount: 80/130/180/230/280
Shield Duration: 10 seconds
Bonus Damage over 2 seconds: 30/60/90/120/150
Mana Cost: 80
Cooldown: 26/24/22/20/18
Shield scaling off BONUS Health: 10%
Bonus damage scaling off AP: 40%

This ability is similar to Shen's W in that it gives a large shield, but it also give bonus damage to any enemy within swinging range of Nautilus over 2 seconds.

ISSUES: Only gave 10% based on 3 flat HP quints and Veteran's Scars Mastery i.e. shield bonus of 10.80. Was not effected by Durability and Juggernaut Mastery.

E: 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.

Damage: 60/100/140/180/220
Slow Amount: 30%/35%/40%/45%/50%
Slow Duration: 2 seconds
Mana Cost: 60/70/80/90/100
Cooldown: 10
Scaling off AP: 50%
Range of 1/2 starting platform on Dominion

The best fit would be Volibear's E, it has a fairly short range that needs to be used while they are close and slows them down.

R: 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.

Pass Through Damage: 125/175/225
Explosion Damage: 250/350/450
Stun Duration: 1/1.5/2
Mana Cost: 100
Cooldown: 120/100/80
Pass Through Scaling off AP: 40%
Explosion Scaling off AP: 80%
Range of starting platform on Dominion

There is no perfect match that I could find, but Sejuani's R seems to be the best match. It deals half damage (half ap scaling) to anyone in the way of the attack. In a way it is similar to Leona's E since the main effect is the last champion hit, but that is not an ultimate and it does not pull Nautilus towards the target.

EDIT: Sequence needs to be followed to get the best results IMO. With W maxed first the cooldown is reduced by a lot which is extremely helpful and necessary. The E does not change cooldown but it gives good damage and slow so should definitely be second and Q does not need more than 1 point to be effective so save that for last.

LVL 1:
Health:518
Health Regen:8
Mana:250
Mana Regen:8
Armor:15
Magic Resist:31
Move Speed:300
Attack Damage:55
Attack Speed:.613
Range:175

LVL 18:
Health:2264-3 HP Quints-mastery(duability, veteran's scars, juggernaut)
Health Regen:17
Mana:1100
Mana Regen:20
Armor:71
Magic Resist:53
Move Speed:300
Attack Damage:111
Attack Speed:.717
Range:175

STATS GIVEN ON LOL WIKI ARE DIFFERENT FROM WHAT I HAD.

CDR and HEALTH are your 2 main goals.
1) CDR at 40% gives you 10.8 seconds on your shield which allows him to do AoE with his basic attack and have a DoT on all targets it hits plus with your high health you'll have a very strong shield (over 10% of total life)
2) Your shield benefits a lot from health so build health.

Thus we get:
1) Frozen Heart, Shurelya's, Randuin's for 40%
2) Warmogs, Shurelya's, Randuin's for Health

Force of Nature will give you immense health regen and magic resist which makes you even more tanky. Merc Treads for tenacity.

Personally I dont think that any of the items can easily be replaced since they are all necessary to hit the main goals of Nautilus. Shurelya's is the only one since you can get other items with CDR and Health because of kindle gem, but I prefer Shurelya's because it builds off philosopher's stone and has a good active on it.

MOVE SPEED + TANKINESS
You are a jungler so Runic Affinity is nice but not necessary and you shouldnt have problems with mana since you'll have blue and later it is not as necessary to have mana regen. Get as much move speed as possible and decreae of damage.

Marks can be anything, Armor and Magic pen are just what I have. MOVE SPEED QUINT ARE NECESSARY IMO.

If you believe that there is a better ability in the same letter placement then please let me know. I am fairly certain that I chose the closest abilities, but I may have overlooked something. *Also if you can figure out the range of the attacks rather than about the starting platform of Dominion let me know. Also if anyone wants to figure out the actual Health at 18 then please tell me.*

I hope this helps you when deciding on Nautilus whether it is buying or how to build him.

Personally like R>W>E>Q with order being Q-W-E-W-W-R-W-E-W-E-R-E-E-Q-Q-R-Q-Q in lane and 0-21-9 mastery page. I love using tanks, so this champ is definitely worth it, but if you hate using tanks then this probably isn't the right champ for you. Frozen heart is definitely worth it IMO, I still don't know what I would build, still deciding on what feels best. Probably Mercury Tread's, probably not Frozen Mallet, maybe Warmogs, Atma's, Force of Nature, Randuin's, Banshee's, Guardian Angel. Still testing out builds but would definitely get boots, heart of gold and philosopher's stone and eventually frozen heart.

If you want to use this information feel free, just give me credit and +rep me.

Description of ability came from the League of Legends Patch Notes.

New things:
Stonewall figured out exactly how to fix him. MOVE SPEED QUINTS. This gets rid of the problem of being too slow and makes his ganks awesome, just dont hit a minion with your Q.

I know I've been stressing it but W cooldown reduced to 10.8 with 40% CDR means you can almost have it permanently up. This will allow you to do so much more damage and sheild more. Frozen Heart, Shurelya's, and Randuin's will get you that 40% or you can try something else but it is nice since it builds off of philosopher's and heart of gold.