Projecting bow sections lengthened carrier catapult runs

Why did some early carriers have two projecting sections at the bow of the flight deck?

They gave the catapults a longer run for accelerating aircraft into the air.

The two projecting sections at the bow gave the catapults more distance over which to accelerate an aircraft. Extending the run forward made use of space beyond the main rectangular flight deck. The unusual outline therefore followed a launch requirement rather than decoration or an incomplete flush deck. This short answer gives a practical reason for one of the most conspicuous features on early carrier plans.