When each player is placing their initial Harbor and settlement, does the first player place BOTH their Harbor and settlement immediately or does the first player place only their Harbor then it's the next player's turn to place one Harbor?
Using the turn order described in base Catan, each player places a harbor settlement first and a regular settlement second on the starting island (each without a road). Your harbor settlement must be placed on one of the intersections marked with a circle (page 9). The regular settlement may be placed on any intersection, including those marked with a circle. You must of course observe the distance rule when building all harbor settlements and regular settlements. Your starting resources are 1 card from each terrain hex adjacent to your starting settlement (not harbor settlement).
The last player to place a settlement is the first to place a road adjacent to that settlement. That same player then places a settler ship (ship + settler) on one of the sea routes adjacent to his or her harbor settlement. The other players follow clockwise. Once everyone has placed their pieces the starting player begins the game by rolling the dice.
I read that first line to mean you play like the base game, you place your harbor and then everyone else does too. Then the last person to place a harbor, places their settlement, with a road and then places a settler ship, back to the original player.