Jajajaja

You build order is odd. You should rush catalyst before building frozen heart/abyssal. You want that sustain on Nautilus. Without getting some health early your Titan's Wrath it is going to fall very quickly. Also, Titan's Wrath ooes more damage than Riptide, so you should max that first.

As a first build i wont downvote, but i dont agree with the choice of eleisa'a miracle. If you need tenacity, you will have needed it prior to this, and if not, you would be better served with something that really increases his tankiness (based on the build. Consider Warmog's Armor instead, which pairs very very well with Force of Nature and your shield. Or you could add Rylai's Crystal Scepter to increase health, AP and give the benefits of slow.

Great for a first build! My first build i believe went 40% XD. I love how you go in depth in your items and why you chose them. I personally don't see heal being very effective on naut late game when he is so tanky, but everybody is different. Sorry to say this but not my favorite naut guide. Regardless of whether its my favorite or not, it is well thought out so +1

Nice guide! Could use some more information, but a decent guide to follow already. You might wanna turn on the "Require comment to vote" button as many people will just downvote without giving a reason.

Keep up the good work!