Why carrier islands helped pilots judge approaches

Why did early carrier pilots fall victim to poor approaches?

Pilots needed experience to judge a moving, pitching deck, and flush-deck carriers deprived them of an island structure that helped show the deck's rise and fall.

A pilot approaches a deck that is moving forward while also pitching and rolling. Without an island, judging that motion and timing the descent becomes more difficult because the pilot loses a prominent visual reference. Training, practice, approach speed, and the carrier's arrangement therefore interact in determining landing safety.