Ah, also, while Tome of Salvation is constantly used as the source for gods, there is a god in ToS that isn't granted any details but is further developed in Tome of Corruption. This is from Page 145 of Tome of Corruption, the Norsca section:
"Curiously, many Norsemen believe in Gods with strong parallels to those worshipped in the Empire, although no Norseman believes in Morr, since the afterlife is closed to all but the most courageous warriors. The Norse versions are always more savage and vicious than their southern counterparts. For example, the Skaeling tribe claims a Daemon God named Mermedus, often believed to be a dark reflection of Manaan, dwells beneath the Sea of Claws. They depict him as a bulbous and ghoulish figure, bloated in death, and covered in bulging eyes. It's said he walks on the sea floor, causing stormy waters to capsize ships and drown sailors. To appease this vile God, the Skaeling make Human and animal sacrifices, casting the weighted bodies down to distract the God from their voyage."
Oddly, Manaan might have the most variants of any of the major Old World gods. Manas, Manalt, Mermedus, Mathlann (or Manaan is a variant of Mathlann), Manhavok (maybe), Stormfels, Olovald (who is likely a different god that was absorbed by Manaan)...
Another note is that there are argumnets in the Cult of Manaan over where Manaan's influence ends. Everyone agrees that Manaan is the God of Storms, Oceans and the Sea. What people argue about is where that ends. Everyone agrees that Manaan is not a God of Lakes, he's a god of streams and moving water and not stagnant water. There are some who say that he is the God of Rivers, but others, such as the Taalites of the Talabec, refute that and say that that is Taal's domain as the Lord of the Wilds.
There are also numerous gods of specific rivers, like Aach the god of the Aach river in Ostland, Bogenraur god of the River Bogen in Bogenhafen, Altaver god of the River Aver, Gorol the God of Streams in Ostermark, Grandfather Reik God of the River Reik in Reikland, Ktharta Goddess of the Lake Delb in Delberz and Wulfor in Ostland God of the River Wolfen. It seems to me that despite the efforts of some priests, rivers are largely unclaimed territory, because it's the domain of several different gods who have a local sphere of influence. I suppose it makes sense considering how vital rivers are to daily life. I doubt most of these River Gods are variants of Manaan.