For 5-6 sea resource starts, your build/tech order is different...
There will be starts where both your luxes are sailing luxes (best is whales + crabs)
But even without pantheon, these are really strong, and early midgame is where you'll see your cap shoot up in pop while still having loads of production with just a lighthouse. Add in a seaport and these become the best non-NW non-GP tiles in the game.
God of the sea is nice, but does not generate faith... and you'll be going for optics before philosophy. Which means later theology. Really hard to get Hagia on deity if you don't beeline.
Even if you do get that pantheon though, chances are you're going to miss out on religion (unless Maya) and hence your pantheon probably won't survive the whole game.