My PCs got into a nasty pier fight with a pack of casters and the Sea Witch in the group got Baleful Poly'd into an armadillo. He also kept his mind intact.
Nothing smells worse than a wet opossum on the half shell!!
They went and begged Tessa if she could help shift him back, which, was perfect to get them back to following spies as payment for the service!
To the OP: I know this is late but I hope your group works out and that your hard work is not ruined. My group is pretty well set for sailing although they have no desire to use Infamy and Disrepute mechanics. I mentioned them several times and they are always a bit confused when the bad guys use them and get small advantages. *shrugs*
I love the ideas here and may have to use some as my PCs are coming up to the Regatta, as soon as they finish stompin the guts out of a bunch of Sahuagin that so richly deserve the beat down. They should do swimmingly as they have upgraded their main ship with all the bells and whistles and with the magic wheel (Jalhazaar's?) they should win going away. I hope so anyway! If not, I am SO using these!
I've also substituted Minotaurs for Cyclops in my campaign. My S&S is run in Mystara with Thyatians and Alphatians being the antagonists.
Minotaurs harassing Tessa is a great idea as that could lead into a 'Forgotten Kingdom' kind of feel as they beat back the invasion and then pursue to discover where they came from and ensure no more reprisals.
I love the Deep Platinum angle and just so you know /swipe! My group just bumped into the Abo at the Brine Banshee and did real well against it with some good saves on the Domination. It fled to the depths to re-plan it's conquests! Plus, I have an Aquatic Elf PC Daredevil Bard so that will be a nice Liberation of the Relatives angle! And who doesn't love smashing Aboleth face in!!! Creepy buggers!
I don't have any set ideas for you at the moment but I will go peruse my library and if any of it looks interesting, I'll hit you back.
Great nuggets of ideas you have already, hope I can help!