This is Respectively my Tanky Jungle Nautilus build. It has taken me some time to get, what i think, to be the best way to play Nautilus as this build allows him to be incredibly sturdy and tank worthy in team fights, as well as a threat to face 1v1.

The rune's I used allow Nautilus to jungle very easily, as well as provide an early tankiness for counter jungle's and early ganking.
I chose these marks because Nautilus's skill's are AP based. I found that it helped me do more damage, especially with Riptide and Depth Charge. I tried the armor pen marks but found the magic pen more useful overall.

The armor given from these seals allow me to run with a regrowth pendent which, in my opinion, puts me further on my build then say the cloth armor/5 potions combo. an alternative to these seals that I found useful were the flat health or health per level, though I found these a tad less effective.

I chose magic per level glyphs as apposed to flat MR glyphs because I found they were more useful in mid-end game. The resistance combined with the armor seals provide easy early ganking survivability and lane cover. An alternative could easily be the flat MR glyphs. I did try using AP glyphs, it provided me with slightly higher damage but, of course, made Nautilus more vulnerable to AP champs.

These quintessences I chose because of Nautilus's incredibly slow movement speed, they allow me to move from jungle mob to the next more efficiently and to cover lanes and gank with more ease. Alternatively i may suggest health quintessence or possibly AP quintessences if you feel you are needing that slight damage boost.

I chose to build my Masteries 0/21/9. I at first was running with 9/21/0, but i felt the Expanded Mind, Swiftness and Runic Affinity to be a more effective approach.

I find these items most effective to Nautilus starting game. The health from the pendent keeps my health up between jungle mob's. I usually will go back to base at level 4 or 5 to get my philo stone and reg/upgraded boots.

Depending on the other team's comp i will pick MT or NT. If they seem to be more AP or CC heavy, MT is a good choice, if more AD then NT is best suited.

I love everything about this item. The item I feel is very well priced for the stats given and the passive works well with Nautilus's abilities, it is also incredibly useful for farming and clearing lanes.

The AP given from this item, though fairly small, is quite noticeable to Nautilus's abilities. The aura is beneficial to not only Nautilus but to other allies, again helpful with clearing lanes and jungle and in team fights. The MR given is a nice perk as well, when fighting an AP heavy team I will sometimes get this item after giants belt, but before sunfire cape to provide more protection.

This item is always my 4th item. The gold provided by philo stone (the build up to this item) is usually unnoticeable at this point in the game because of how easily creeps are farmed. The use ability has proven to be quite useful in chasing down enemies or providing allies and myself with more of a chance to escape a losing battle, also the bonus stats are fairly cost efficient.

The 5th item is heavily influenced on how you and your team is handling the opponents. By this time it is usually clear which champ is doing more/less damage to you, and in which area you are needing more support in. If their AP champs to be fed and building well I will usually Take a Force of Nature or a Banshee's Veil. If AD is the problem at the moment then Frozen Heart is a good choice.

The final item. Again a situational choice. If I am currently the "main tank" in my group I will generally go for a Warmog's Armor for the additional health and boost to my Titan's Wrath. If I am taking the role of an off tank or an opponent has been grossly fed, the additional MR and armor provided from Guardian Angel can be an effective counter, as well as the passive ability helping with survivability.

Staggering Blow is Nautilus's passive that allows his first strike on an enemy stun them as well as deal additional damage. This is very useful for ganking enemies, but also used defend fleeing allies or stopping enemy runner's from escaping.

Dredge Line allows Nautilus to drag enemies and himself closer together. If Dredge Line is to hit terrain instead, the cool down is reduced considerably for Nautilus to use again if needed. I try to save this ability for fleeing enemies rather then initiating with it unless I feel I can take an enemy by surprise and effectively kill them. It can also be used defensively by dragging yourself to safety when being chased or overwhelmed. I always put my 3rd point in this skill for ganking, but I max it out last.

Titan's Wrath applies a shield to Nautilus (which is effected by his bonus health stat) and while the shield lasts it adds an aoe damage over time effect that hits enemies around him. I take this stat at level 1 to kill the additional minions with the blue buff golem's and for the added protection, but don't end up maxing out this ability till level 13.

Riptide causes an aoe effect, damaging all enemies around Nautilus for magic damage, and slowing them for 2 seconds. If used correctly after Staggering Blow this ability can help secure a kill for you and your allies. This ability is also very effective for clearing creep waves or jungle mob's when covering a lane or running jungle. I put my 2nd point in this skill and max it out at level 12.

Depth Charge is Nautilus's ulti. It does a considerable amount of damage to enemies in the path, as well as additional damage to the targeted champion, and knocks everyone in the path up into the air. When used in a team fight I use it on the furthest back champion to get the most use out of it. I take this ability at the usual 6/11/16.

I chose to keep my Titan's Wrath and Riptide at equal ranks till maxed out. I tried maxing each by level 9 on different occasions but, having a low amount of bonus AP, it felt that the untouched skill was lacking too badly.

Flash is one of the Summoner spells that I chose for Nautilus, for what I think, are quite obvious reasons. The utility of Flash allows you to catch up to fleeing Champions, or escape from bad situations.

Smite is a must have when using this build. The blue buff golem at the start proves to be quite challenging without it and takes a lot longer to kill then necessary. Not only on the blue golem, I use smite on the golem's at the end of the jungle as well to speed up the process as you move Nautilus through.

Teleport can be useful if you are needed to cover lanes a lot. Also if you are warding the river/jungle it can provide more mobility for ganking.

Ghost can be an OK sub for Flash. The mobility boost provided can help you escape from sticky situations or catch up to fleeing enemies, though I myself do prefer Flash.

I always start off with the blue buff, getting a leash is helpful but not required, if no leash is used you will be required to drink your potion during this encounter. After the golem I am level 2 and can easily handle wolves and wraith's. By the time i reach the golem's at the top (purple side) or bottom (blue side) my smite is usually up and I burn it on the larger of the 2 golem's. Once the golem's are taken care of I should now be at level 3 and have 1 point in Dredge Line, if one of our lanes requires a gank then you should easily be able to do so at this point. If no gank is required then I return to the wolves and work my way back up. This second round through though, if my health is above 3/4 and my smite is up I will take the red buff rather then going to the golem's. After the 2nd lap through I am usually level 5 (or very close) and have enough gold to upgrade my pendent to a philo stone and get reg/upgraded boots, depending on whether the gank was a success or not. After philo stone is bought you should not need the blue buff anymore so call out to your mid to come take it when he reappears. Continue on clearing the jungle and covering lanes/ ganking when possible.

Pro's:
Great initiator
Very tanky early-end game
Great CC
Easy to farm/jungle

Con's:
Very slow early game
Easy to KS allies (unintentionally)
Dependent on blue buff early game

I hope that this build works out for you as well as it has for me. I am a strong believer of "dont knock it till you've tried it" so please consider it before jumping to conclusions. This was my first full guide so pointers on the build, and how the guide has been laid out, are greatly appreciated. thanks for reading! =D