Out of Character Discussion
The #1 mistake people make with bards is they forget to make sure they're combat-capable. Bards aren't full casters and shouldn't pretend they are; you need to have something to do during combat other than cast spells and play your banjo. (The other mistake is to use an instrument-based form of Performance, but I see you managed to dodge that one!) Unfortunately in an underwater campaign the usual strategy of an archer bard isn't going to work. I've heard it's possible to make melee bards but I'm less familiar with it.
I can tell you that dumping Strength probably isn't a good idea, even if you're planning to use Weapon Finesse. An Oratory bard doesn't need Wisdom (you get the second-most-important Wisdom skill from Versatile Performance, and you have good Will saves anyway); dump that instead. And you can't use Weapon Finesse with your snapping shield, anyway. Actually the whole snapping shield, while quite cool, is probably not going to work: you can't cast spells or even temporarily hold your rapier with that hand. Casters mostly can only use light shields for this reason. You can drop Weapon Finesse but you still can't afford to dump Dexterity, because you can't wear heavy armor. At least at low-level, most of the best choices for feats fall under the heading of "boring, but practical": Dodge, Weapon Focus, Toughness, Great Fortitude (or whichever of your saves needs help), Improved Initiative, Alertness, &c.
I... don't know that it's worth the point-buy cost to get to Charisma 19. It certainly matters more for bards than clerics, but it's VERY expensive. I really don't know about this one; I could be wrong. 20 definitely isn't worth it but there are some solid arguments for 19. Up to you.
Especially with Constitution 12, you can't afford to be taking skill points as your favored class bonuses. Sorry. Those two HP are important. Also, you forgot to include your Con bonus in your HP in the first place!
Keep UMD maxed. It's one of the bard's main features. Spellcraft too (all casters should keep Spellcraft maxed, even clerics!). Drop some extraneous Knowledges if necessary; you can pick them up later. I know those class skill bonuses are tempting but they'll still be there when you get around to it! Even if you're planning to take Versatile Performance (dance), seriously consider a point in Acrobatics. Tumbling is just that important for light armor characters. Also, a lot of your final skill modifiers are wrong; go through and recalculate them.
Your spell DC depends on the spell's level (and in some cases on the individual spell!) but DC 15 is correct for 1st-level spells. Non-scaling blasts generally aren't worth it for spontaneous casters, although chord of shards seems insanely overpowered for a 1st level spell. But still, 2d6 will fall off pretty quick (especially with Reflex negates) and then you have a dead spot in your repertoire, at least until 5th level when you can retrain it.
You can't (technically) take Savant; it has a background requirement (Kitharodian Academy) that you don't qualify for. There's probably no reason Zag wouldn't want to override this. You definitely can't take both Savant and Grim Optimism because they're both Basic (Social) traits.
You need to choose a lot more languages: 2 starting languages for high Intelligence, plus one more for your point in Linguistics.