Nice. You've taken something not often explored and made a cool build around it. Nice work

Thanks for kind words everyone. I have made a few small changes here and there in the write up. To see some of the best builders on this site liking my build is really nice. 

This is awesome! I don't think I've seen a build this unique in a long time, this type of thing restores my faith in first time posters! You did a fantastic job with this guy. The restrictions you put in are really suitable, and fit perfectly for an Argonian character. Since I'm a bit of an Alchemy buff I'd love the challenge of creating potions and poisons with a specific set of ingredients. It's almost like using the Greenhouse to only create potions with grown ingredients but far more meaningful to the character by having to use things only found in the water, where you happen to frequent the most. Expect me to spend the next half hour going through my Skyrim guide to see the possible combinations for potions and poisons! +1

I love how you create potions specifically from lake and riverbeds. This is some cool roleplay for a build and you've really put that racial ability to work and built around it. Blackreach and the Forgotten Vale both have extensive water systems and tons of things to explore. They're definitely worth mentioning :)

The focus on just kind of doing your own thing and avoiding the big questlines in favor of roleplay sounds really immersive. Also, I have to say this is one of the only builds I've ever seen that actually does something with Skyrim's many waterways. I had no idea how much was down there until I looked. Pilgrim's Trench especially was fun. All in all a very cool build with a fun concept, although I worry it might get stale after a while. Ah well, not for me to judge. I'll contribute my likes regardless. Great work!

I should have mentioned this somewhere in the build, but the reason I went with something simple is I just wanted something simple to play. A lot of the time my characters are very complex or rely on crafting. I have played a lot of builds on this site, and they are all awesome. However, a lot of the time it seems as if I am going through a check list while playing. This is done, now on to this etc. 

With Alchemy it would be very easy to add in a few more things, but then the slippery slope of saying "well maybe that too" comes into play and before I know I'm back picking up stacks upon stacks of ingredients :)

Blackreach is a wonderful area to take this character, I wanted players to make it there on their own. It is sorta the ultimate deep dive in a way. The alchemy passive you can get from there would also work very well. 

This site has soooo many complex, and well planned out characters I just wanted to make something simple and easy to play as that's what I was looking for at the time. It's nothing ground breaking for sure, it just explores some lesser traveled areas, and using ingredients that I personally never used for the most part. The grass pod one is very tempting, believe me every time I walked past one... 

Thanks for the kind words everyone. 

Yeah, this is a really cool character for just relaxing and exploring. You could probably also go with a different race and use Waterbreathing since you are using Alteration anyway. 

I love this! I'll follow with detailed feedback later but for now my +1 is yours :)

Oops. Clam chowder, it does have a soothing feeling when consumed.

OK, here is the promised feedback  

I like the simplicity in the goals of the character and also how you added caves into the mix. I once tried a similar character without exploring caves and it ended up being somewhat boring. However, caves add a necessary layer of locations to explore and in some cases can result in something similar to some diving bell missions in AC4: Black Flag - one of the best things in that game IMO. The one cave near the northern cost comes to mind - it's actually three caves interconnected with a leap of faith and underwater passage 

I have a few ideas on how to improve this which I'll list in a bulleted list for convenience.

• They also have a starting bonus in several skills – I'd remove that line. Argonians get boosts only to Lockpicking and Alteration of the build’s skills and Alteration is not perked. Here is how I'd write it: The build is based around the Argonian ability to breathe under water and their Histskin ability is a life saver when you encounter something beyond your ability to deal with.

• The Deep Diver does not use shouts. However, Aura Whisper, or Whirlwind Sprint would work. – no point in listing shouts that the character doesn't use. If the user decides to add them, he’ll do it regardless. You describe the character you've played 
• A potent Toxin that slowly drains the life from the inflicted. Once the target is poisoned, the Deep Diver can hold his guard while his foe is weakened. - I'd change it to this: This potent toxin will slowly drain the life from the inflicted and weaken them while the Deep Diver holds his guard.

• The Deep Diver's use of this magic is limited to just two spells, Candle Light and Transmute Ore ( found in Halted Stream camp). – I’d remove that line. You convey the same information after the image. To fit with that change I would've also reworded the next sentence: His limited skills allow him to cast but a few spells - His limited skills allow him to cast but a few spells - Candlelight and Transmute Mineral Ore

• Attrition:
  Required, Tetrodotoxin,High Block skill, concentrated poison. Strike your foe once with deadly poison, hold your guard until they are weakened, and strike again for another application.
  To The Depths:
  Required, HistSkin, Deep body of water. When the odds are not in your favor flee to the depths. Activate Histskin for a massive health recovery and either strike again, or slip away.

  I’d change formatting here, like this
  Attrition: Tetrodotoxin, high Block skill, Concentrated Poison.
  Strike your foe once with deadly poison, hold your guard until they are weakened, and strike again for another application.
  To The Depths: Histskin, deep body of water.
  When the odds are not in your favor, flee to the depths. Activate Histskin for a massive health recovery and either strike again, or slip away.

For your tags, you can use up to three tags from Character Building Archives, one Race tag and one mandatory Rank tag. For your current tags it'll be:

Race:Argonian, Rank:Bloodworks, "Character Build Rogue"

You can add another two Character Build tags, it'll help your build to appear in more places. I'd suggest "Character Build Alchemist" and "Character Build Pilgrim" tags but it's entirely up to you 

And finally, an advice regarding Alchemy. Ben C suggested adding some ingredients, which might be beneficial but I can see how you might be conflicted about those. I suggest adding three other ingredients that fit the rules you have set - Cyrodilic Spadetail, Small Pearl and Pearl. The first is found alongside River Betty and Silverside Perch while the last two can be found on the shorelines of Solstheim. With those three ingredients you'll be able to craft:

Fortify Block, Restore Stamina, Resist Frost - Pearl + Slaughterfish Scales + Silverside Perch/Small Pearl

and

Ravage Health - Cyrodilic Spadetail + Silverside Perch

P.S. I also took liberty of fixing some grammatical mistakes here and there in the build. I attached a notepad file that details the typos.

P.P.S. Check out the HTML trick on how to make text to align vertically next to the icons in the CB HTML & CSS Guide