Encounters on the Savage Seas II is a sourcebook full of interesting and thought-provoking encounters for seagoing adventures. From cursed ghost ships based on legends of the Flying Dutchman in The Horror Adrift to fun underwater racing in Aqua500 to fighting (or merely surviving) a primordial force older than known history in The Living Storm, this book has it all. It even includes a few extra sea-related creatures and magic items, in addition to those presented in the adventures themselves.
However, there are some minor issues with numbers involved, especially as they pertain to CR and difficulty of encounters. For example, in possibly one of my favorite encounters from the book, The Half Moon, in which the party must survive an attack from a naval necromancer and his army, it lists the recommended Average Party Level as level 7. However, the final fight includes 20 modified Ghouls (CR1 each) and a Necromancer (CR9) in case the party finds it too easy. The adjusted XP for such an encounter is more than 4 times the "Deadly" experience threshold for 5 level 7 characters (using the encounter calculator found in the Dungeon Master's Guide).
EDIT: I have since taken a second look at this encounter and seen that the party has help in the form of the crew, which is a considerable aid. This encounter is fairly balanced with a cohesive enough party composition.
Furthermore, a couple of entries in the book have numbers or words that just don't make sense. Take the Hypno Fish (Pg 89), for example. While the anatomy and physiology of the creature is fascinating and I can't wait to put it into one of my games, its written stats are confusing at first read-through. It has 1d4-1HP and its only attack deals 1 piercing damage, but a single one is written to be CR 8. However, having a swarm of them (which changes the HP to 8d8-8 and damage to 4d6) reduces their CR to 1.
Overall, I would recommend this book to any DM who wants to include sea travel and seaside locations in their game. However, I'm knocking one point off because many parts of the book must be altered in order to properly utilize them. Don't get this if you're just looking for something you can just pull encounters from right at the table.
EDIT: I'd just like to add that, since the posting of this review, the publishers have taken the initiative to take another look at their product to ensure that it is up to standards. They have not yet completed the revisions, but their willingness to work with customers (combined with my admitted faux pas in reading earlier) is enough to grant them an additional point in my eyes. A good product from a great publisher.