When creating a Water World superflat world, the player spawns at the bottom of the sea

The Bug:

Player spawns at the bottom of the ocean in Water World flat preset.

Steps to Reproduce:

Create a new flat world with the Water World preset.

Expected Results:

The player would spawn at the top of the ocean in the Water World preset.

Observed Result:

The player spawns at the bottom of the ocean in the Water World preset.