I asked this question, but screwed up and hit enter halfway through. Anyways, here's the full thing:
When Jacob and the MiB are sitting on the beach in "The Incident, Part I" the ship is seen not far off shore in clear skies and daylight. In "Ab Aeterno" the Black Rock arrives in a storm at night. Howcome these two ships are both credited as the Black Rock, as per the "The Incident, Part I" lostpedia page?