I like "The Stormers" maybe with a different modifier than "Silver"The Stormers or Silver Stormers
Basic and straightforward, but works. They could be the Free Company of Curia (the capital) but have locals start calling them "of Saltmarsh" instead, which might get the PCs' goats.The Free Company of Saltmarsh,
Lavinia's Titans?.
The Favoured Few
I like this one, too.The Titus Tetrad (the Tetrad for short)
Heroes of the Salt (i.e. coastal adventurers)
something like "Titus' Dependable Adventuring Company" - "The Dependables" for short
These guys should really be doing something apart from drinking in celebration? Maybe they specialise in defending places and training local militia?
You could have a group of local NPCs. Something like the Boy Scouts. Call them " Protector Cadets" All the local teenagers want to be in the cadets and get cool uniforms and weapons training.
(This seems like something which a tactician would recommend to the Prefect of Saltmarsh)
Bob’s group of allies