No problem friend I'm happy to help, if you have any more questions feel free to PM me to ask anything. Good luck!

Well I know it does stack, but still imho you are getting far better stats with Rod of Ages than Rylai's Crystal Scepter I mean:
Rod of Ages = 3035 gold, good passive, 630hp & 725 mana + 80 ap when fully stacked.
Rylai's Crystal Scepter - 3105 gold, 500 hp + 80 ap + mostly 15% more slow, because Nautilus abilities are mostly AoE. I know, it's good, but you really don't need this slow, u have enough cc without it, and if u need to slow some one down really hard, u have Randuin's Omen active, which almost immoblizie enemies when used with Riptide
Thats why I prefer to pick even double Rod of Ages instead of Rod of Ages and Rylai's Crystal Scepter, but I must say that it's reasonable item for naut -> if u really need this slow.
And about farm - I didn't say that i have better farm than my mid. I just meant that your farm will be good enough to get this Rabadon's Deathcap without pain.
Thanks for +1 and your opinion, it was helpfull ;)

Okay, I'll explain a little to you here. You start at wolves then move to blue with help from your team. It is their job and yours to protect your buffs before minions spawn, if you do this correctly, you will not be counterjungled unless you lose a level 1 fight. The Regrowth pendant -> philo stone is for solid regeneration during your roaming phase, because beyond level 5 you can farm the jungle creeps with Titan's Wrath without losing any health, making pots unnecessary. Trust me, I have tried Cloth Armor, and with Nautilus' high base armour and your armour seals, he's very flexible, note what I said. Now I personally build Nautilus as a bruiser with none of these items, but for your AP-tanky build I'm recommending Rylai's Crystal Scepter in addition to Rod of Ages, not substituting it, for both its stats and its slow. The slow DOES STACK with the slow from Riptide, it also procs on the DoT from Titan's Wrath for when your Staggering Blow is on CD for that target.

Also just a general fact, jungle mobs do not give more gold, and if you have more farm than your mid lane, he's a ****ty farmer. I'll +1 you for the changes you made to your guide, you obviously put work into it, although I respectfully disagree with a few of your points, that's what this website is for, different collective ideas.

Huge update was here today. ;)

@CombatJack1
Changing runes and going to jungle with Regrowth Pendant isn't good choice. You'll be jungling much slower and if you will get your blue invaded or counterjungled it's way harder to come back. When jungling with those runes & Cloth Armor + 5x Health Potion it's better. Try it and u will see the difference. The thing about Rabadon's Deathcap - u will have enough farm, for taking it - jungle mobs gives more gold & u are king of assists. How about Rylai's Crystal Scepter - I think this item is actually almost useless on Nautilus - You don't need this slow - u have enough slow from Riptide+ Randuin's Omen, for hp and ap better choice is Rod of Ages. I would possibly take Will of the Ancients in lategame, I will try it and tell you my thoughts, because it sounds like good idea.
And I've found some time and changed that 'wall of text' to something... better? :)

I think your guide right now could do itself justice tremendously with coding, I can't tell you how many new builds I've commented on who have just walls of white text exactly like yours. It makes me wonder if people actually read other high rated guides before writing their own. Please review the options you have with coding through this site, there are multiple resources out there as MikhaelSoras indicated as well. Also don't label your tanky build as the "doing bad" alternative, because in many (most) instances you will be the team tank and initiator and you don't want newer players interpreting that as the second option if you're sucking, because it's not. Also Nautilus actually has a few options for starting items in the jungle, and you might want to try Regrowth Pendant and a health pot for an earlier philosopher's stone. He's very flexible with the right runes, try it. Also even if you're doing well, I don't recommend Rabadon's Deathcap as it's just not that necessary on him, you can't possibly get the farm of mid lane and it means you just spend 3600 gold on something that doesn't help your team at all, when you could alternatively get Rylai's Crystal Scepter for the slow or even Will of the Ancients to really buff your caster.

No problem, when you make the updates PM me, i will enjoy see your guide

Take a look at my ezreal guide if you have time.

Thanks a lot for +1, I will add some pictures and improve this guide in a few days :)

Good guide but its a wall of text you should puts some pictures and icons. i will give +1 for you , to encourage you to update it.

Try this link to improve your guide(jhoijhoi) How to make a guide