Scenario 3 of the Seafarers expansion to The Settlers of Catan is The Fog Island, in which players "discover" the hexes in the middle of the game board by building a road or ship that connects to the intersection of an unexplored hex. The discovered hex may be a land or sea hex.
The Road Building Development Card can be used to build two roads or two ships or one of each. I had a situation in which I was in a position to build a single road/ship to discover an unexplored hex, or a single different road/ship to discover a different unexplored hex. I also had the Road Building Development Card, so I could build two roads/ships at once. The question is:
Must I build both roads/ships from Road Building immediately and then uncover hex(es), or may I uncover hexes as I build the two roads/ships?
Put another way, can I build one road/ship from the Road Building Development Card to uncover the first hex, and then use that information to make my choice on where to build the second road/ship from the Road Building card?
As the player with the Road Building card I would prefer to uncover hexes as I build roads/ships so that I can make a more informed choice for the placement of the second road/ship. If the first uncovered hex is a sea hex, for example, I will probably prefer to build the second road/ship to uncover the second hex. But if the first uncovered hex is a land hex with a high probability chip, I might prefer to build the second road/ship alongside it in preparation for building a settlement.
The text of the Road Building Development Card seems to imply that the placement of both roads/ships occurs at the same time, in which case I would have to build the roads/ships before uncovering hex(es):
Place 2 new roads as if you had just built them.
However, the rules for The Fog Island scenario (page 14) states (emphasis added):
If you place a ship or road that connects to the intersection of an unexplored hex, you must immediately draw the top hex from the pile and place it face up in the empty space.
My opponents and I agreed (before I placed any roads/ships) that I could uncover the first hex before placing the second road/ship, based primarily on the use of the word "immediately" in the scenario description.
Is this the correct interpretation? Is this specific question addressed anywhere else? The rules for Seafarers has a small section on the Road Building Development Card, but only to say that it can be used to build roads and/or ships as opposed to just roads. Similarly, the online FAQ for Seafarers does not address this situation.