This book/pdf is 82 pages, 1 page front cover (in the dead-tree version blank inside), 1 page editorial/ToC, 1 page advertisement, 1 page SRD, 1 page back cover. That leaves 77 pages of content.

Disclaimer: I was a patron of this project but due to real life, didn't contribute that much to this project.

The pdf is full-color with some b/w artwork here and there, while the dead-tree version is b/w.

The book kicks off with an informative 2-page introduction to the creation of the aboleth as a monster by David "Zeb" Cook, its original creator.

Then, we get a chapter of 8 pages on lost cities in real world myths and legends, namely Atlantis (D'uh), Lemuria and Mu. This chapter also details a sample lost city, Ankeshel and the city of archeaologists, tomb-raiders etc. that spawned from it, Cassadega. 1 page is taken up by an absolutely gorgeous, full-color map of the twin cities. While I didn't care too much for the information on real world empires (most of which I already did know), I loved the Ankeshel-write-up and think that most people may benefit from this chapter.

Chapter 2 deals with pelagic Characters, i.e. characters that are especially competent/adapted to frequent underwater expeditions. (14 pages)
Within, we get a new race, the Maerean (Half-Merfolk), who gets +2 to one ability score, low-light vision, multitalented, keen senses, count as both merfolk and human and are capable of living both in water and on land. This race left me under-whelmed, probably because of my utter hatred of "environmental races", I.e. races that negate environmental perils. HOWEVER: This race does not really negate cold or pressure, so it does not wholly fall into this despised category. We are, thankfully, spared aquatic dwarves and gnomes and the like and instead get some cool and useful bits and pieces: All the classes get alternative class features for pelagic characters. Barbarians get rapid swimming as well as 7 new rage powers. Bards get 3 new bardic performances. Clerics get 5 new domains (Deep, Glyph, Fish, Ocean, Sea Monster). Druids get advice on aquatic animal companions and rapid swimming. Fighters get underwater armor training, a bonus to swim checks and aquatic weapon training. Monks get a new ability for their Ki pool, fast swimming, can prevent animals and magical beasts from attacking them, get more breath, gain "Ki swimming", water walk and later can even turn their body to water. Paladins can use lay on hands to replenish breath and grant weapons the "Wavesplitting" quality as well as get an aquatic mount. Rangers get access to the net-and-trident combat style, can move easier through difficult terrain, get better at killing undersea foes and scent. Rogues get 6 new Rogue Talents and 3 new advanced talents. Sorcerors get3 new bloodlines: Aboleth, Vril and Ocean. The Aboleth and Vril bloodlines count amongst the best bloodlines I've read so far. Wizards get two cool new schools, the glyph school and water school. Both arcane casters can profit from the new familiars presented later in the book.

We also get a bunch of new feats:

Aboleth Spawn - Use acid splash as a spell-like ability
Antiquarian Tinkerer -Use Disable Device to operate ancient technology
Aqualung - Hold breath for extended duration
Artifact Hunter - +2 bonus on Appraise and Knowledge (history) checks
Bioluminescence - Use hypnotism as a spell-like ability
Born to the Water - Increased swim speed; +2 to Con checks
Call Leviathan - Add template to summoned aquatic creature
Castaway - +2 bonus on Knowledge (nature) and Survival checks
Cranial Manipulation - Increase number of Hit Dice affected by enchantment spell
Deep Diver - Decrease damage from cold and pressure
Depth Affinity - Immune to cold/pressure damage
Elemental Connection - Spells cast in water are more powerful
Fisherman’s Eye - +4 bonus on Perception checks underwater
Fish Skin - Heal at double rate when in water
Glyph Familiar - Your familiar also benefits from personal spells
Glyph Reader - +4 bonus to operate ancient technology and magic
Hydromancer - Add water descriptor to prepared spell
Improved Net Fighter - Control entangle opponent as a move action
Agile Netter - Opponents in net are flat-footed
Ioun Stone Bond - choose ioun stone as your bonded item
Leviathan Slayer - +2 to attack/damage against Large aquatic creatures
Like an Eel — Make Acrobatics checks instead of Swim checks
Long Distance Swimmer - +4 bonus to avoid non-lethal damage when swimming
Merchant Adventurer - +2 bonus on Appraise, Diplomacy and Linguistics checks
Net - +2 to DC of check made while entangled
Pattern Glyph - +1 to DC of pattern spells
Quick Brace- wielding a Brace weapon as immediate or swift action
Quick Fold - net Fold a net as a move action
Rebuke Sea Creatures - Channel energy can be used to make aquatic creatures flee
Roil -Channel energy can be used to create area of turbulent water
Rigging Monkey - +2 bonus on Acrobatics and Climb checks
Sea Dog - +2 bonus on Knowledge (geography) and Profession (sailor) checks
Strong Swimmer - Bonus to Swim speed.
Swim-by Attack - attack while swimming
Underwater Caster - +4 on concentration checks to cast spells underwater
Unhampered Casting - Bonus to cast spells underwater without components
Vril Heritage - Use mage hand as a spell-like ability
Water Fighter - No penalty to attack with selected weapon underwater
Waterstep - Briefly walk on water
Waterwise - +2 bonus to Knowledge (nature) and Perception checks
Wave Fighter - Ignore underwater fighting penalties for one weapon group
Will to Live - Use Will save instead of Constitution check to avoid drowning
Metamagic
Englyph Spell - Add glyph spell to other spell
Shielded Spell - No concentration check to cast spell underwater

None of these feats felt over-powered and all have their place and contain their own little stories/information on the characters and even better, come with a little bit of cool fluff at the beginning - Nice! Also: I'd probably take Aqualung just because the name is a nice nod to Jethro Tull. ;P I also liked the new ranger fighting style that could also be used in gladiatorial settings. However, several typos and minor editing mistakes (e.g. "Avoiddrowning"[Sic!]) have went by the proofers here, somewhat impeding my enjoyment of the chapter.

Chapter 3 deals with new aquatic equipment and technology of lost cities. (12 pages). Oh boy. THIS CHAPTER ROCKS!! Big time. You get new armor, weapons and equipment, from seashell armors over diving suits to several new weapons. And you get an awesome smattering of new special & alchemical substances like a stick with an explosive coral at the top or shoggoth polyps. Each of these little items spawned some great idea in my mind and made me want to implement them right now. They are gold, pure and simple. We also get Orichalcum as a new material for weapons, armor, etc. and new lost technology in the form of Ankeshelian Vril weapons and associated equipment. Oh boy do they succeed at making far-out weapons feeling both like technology and yet utterly alien. Their firearms rocks and don't feel at all like gun-powder weapons and for all of you who don't like rifles and the like: They are powered via special vril batteries and you can easily restrict/ ban access to these in your home-game. This is one of the most concisely-written equipment chapters I've ever read. My only gripe here is: I want more!

See product discussion for the continuation of the review, it won't fit here.

This product is 82 pages long. It starts with a cover, credits, and ToC. (2 pages) Next it gets into a forward by David “Zeb” Cook about the creation of the Aboleth. (2 pages)

Chapter 1 – Lost Cities of Myths and Legends. (8 pages)
It talks about varies lost cities from real life and stories about them. It gives some details on Atlantis, Lemuria, and Mu. As well as talking about the fantasy lost city of Ankeshell, including a map and brief history of the city.

Chapter 2 – Pelagic Characters (15 pages)
This section talks about races and classes for a campaign set for exploring underwater. It includes a new race Maerean(half merman). Changes to core classes for a campaign focused on this. Including 45 new feats,
New Domains
Deep
Glyph
Fish
Ocean
Sea Monster

New Sorcerer Bloodlines
Aboleth
Ocean
Vril

New Wizard Schools
Glyph
Water

Chapter 3 – Aquatic Equipment and Lost Technology (12 pages)
It starts with Aquatic items 11 new weapons, 8 new armors, 25 new equipment items. Next it moves onto lost Technology 8 new weapons, 3 new armor, 5 new equipment items.

Chapter 4 – Spells and Magic Items (17 pages)
This section has 37 new spells and 42 new magic items and 6 new magic item properties.

Spells by Class
Bard – 7
Cleric – 7
Druid – 15
Sorc/Wiz – 37

Chapter 5 – Sunken Environment (6 pages)
This section is all about how to run campaigns that explore underwater. It has encounter tables, hazards, and advice on how to run campaigns.

Chapter 6 – Creatures of the Deep (17 pages)
This section has 16 new monsters including 3 new familiars, 10 variations of existing monsters, and a ecology of the Aboleth.

It closes with a OGL, 1 page ad, and back cover. (3 pages)

Closing Thoughts. This is very well written the art ranges from good to very good. The layout is nice and it is a pretty book. There is far to much to get into a lot of detail on most of the stuff. The equipment was for the most part good, interesting and fit. Same with the magic items and spells. The history and information about the three real life mythic lost cities while interesting could have easily been left out.

My only real critic is I thought chapter 5 was way to short. What is there is good but a little sparse. I think they could have easily doubled the page count to help GM's out with more information and advice. So while it was a very good book and if you are interested in running a campaign or even a few adventures under the water then it is a good pickup for the price. But it was a little light on GM help to run such a campaign so I am giving it a 4 star review. Good but with a dozen more pages could have been fantastic.

These comments pertain to the PDF version.

I must echo the positive elements that are already mentioned in other reviews: LOTS of information regarding undersea and by-the-sea adventuring. Feats, hazards, equipment, spells and magic items will keep GMs and players happy for sessions to come. For the existing races and classes, there is substantial information to add new dimensions and flavor campaigns as individuals see fit. The addition of a new 'half breed' race is also well suited for play, and not just ocean-centric campaigns. The cartography is also masterfully wrought. It seems that the bonus of the PDF is that the map is color.

Two disappointments I would like to highlight: Whilst evocative, the map of Ankeshel/Cassadega would benefit from being of a higher resolution. There is some lovely detail in both the shoreline and the shallows, but is unfortunately lost to pixellation, even at only 125% magnification.
The second thing is a minor quibble: The Open Gaming Content appears quite small and in the case of the bestiary, unusually specific as to what a prospective Third Party Publisher may use. By my reading of Sunken Empires' OGL statement (regarding the Bestiary), it appears that whilst Defense/Offense/Statistics/Tactics/Ecology may be used as OGC, the omission of 'Name' and 'Special Abilities' make me believe that those items be considered Product Identity. I am likely wrong, but my point is that I need clarification after reading the statement.

Despite the negatives being wordy, I have only deducted 1/2 a star for each. I would heartily recommend Sunken Empires to anyone, be they looking for some inspiration for a new campaign or to breathe more life into an existing one, world building, or even just interested in making their next character a little different. 4 out of 5 stars from me.

The work opens with a foreword by David 'Zeb' Cook in which he muses on the durability of his invention, the arboleth - a monster with an almost-thirty year history and which features large in this book. Then Chapter 1: Lost Cities of Myth and Legend explores the inspirations for this setting. Legends of fantastic civilisations lost to the deeps provide plenty of ideas, after all, as well as a compelling lure for characters looking for somewhere to explore. For that's the intent of this setting: exploration, rather than somewhere to actually live as a denizen of the deeps.

The legendary civilisations of Atlantis, Lemuria and Mu are detailed, along with thought-provoking ideas on how to use them as inspiration for your own sunken empire, before the text launches into the design of a new lost city called Ankeshel for your charaters to research and explore. Ankeshel draws on both real-world myths and the Pathfinder setting, with some Theosophist theories mixed in for good measure, including the concept of vril. The original human inhabitants were taught magic and mathematics by a strange tentacled, 3-eyed amphibious race. Needless to say, it all ended in tears and the city was lost... until recent discoveries began to bring tantalising glimpses of what once was back into general knowledge. Meanwhile a modern settlement has arisen on top of the ruins to provide a base for adventures.

Chapter 2: Pelagic Characters starts with a new race, the Meareans or half-merfolk, ideally suited to underwater exploration and with a few other ideas to make maerean characters predisposed to wish to explore! The discussion moves on to adapting existing classes to better suit such exploits, basing the adaptations on such concepts as modifications due to being raised or living in coastal areas where great familiarity with the sea would be an advantage. There are new clerical domains, for example, and plenty of water-oriented class skills and new underwater feats.

Next, Chapter 3: Aquatic Equipment and Lost Technology is a heady mix of gear you might use exploring under water and goodies that you might find there. The 'ancient technology' is even more fascinating, and the rationale used in its design is discussed, empowering you to come up with more along the same lines. When you are playing a fantasy game anyway, to come up with concepts that will be 'fantastic' to the CHARACTERS rather than the PLAYERS can be quite a challenge, but one that is well met here. This is followed by Chapter 4: Spells and Magic Items. Most of the spells have some aquatic connection, some are to do with glyphs - wound into the ancient writing of the original denizens of Ankeshel is a system of magic glyphs and some astute spell casters may learn the art of their manipulation. The magic items section concentrates on those which survived the fall of the ancient civilisation, with many suggestions as to how to make these as wondrously strange as the lost technology described earlier.

Chapter 5: The Sunken Environment looks beyond the specific challenges to the sheer wonder and strangeness of adventuring underwater. While players might watch the Discovery channel or be SCUBA divers themselves, it is a wholly new environment to their characters. Likely resources available to adventurers are discussed by level, a handy approach both in planning adventures or when planning to undertake them. This moves on to a look at the various environments from coastal zones to deep depths, detailing precisely what you'll find there, challenges and opportunities alike. Next, Chapter 6: Creatures of the Deep provides some interesting new beasties to populate the depths... and a full-blown ecology of arboleths to complete the chapter, and the book.

More than merely presenting a novel adventure setting, this book sets out to equip the GM with the tools to set his own stamp on what could well become memorable adventures, demonstrating how to create a feeling of wonder even amidst what is already a fantastical alternate reality.

Great material. Very interesting approach to undersea adventuring, and I really can't add to the two previous reviews, they did a good job of praising the product.

The only thing I didn't like about the book was the map of the sunken city. I've never been a big fan of the black and white format of the Open Design published products when it comes to their maps. The map would've looked a tad less confusing and much more evocative if it was in color.

I also wish there were some stat blocks for an actual Ankeshelite.

I'm being a nit picky son of gun.

Regardless, a great sourcebook and I certainly don't regret purchasing it what-so-ever.