Looks like it's a good few thousand feet in the air still based on those white caps. They look like what you see from a plane. But it's pointing in the right direction. Very cool.

In the raw video, the engine shuts down at 0:23, and before that you can see the engine blasting the water. It's not coming down that fast, so I'm pretty sure it's a lot lower than a few thousand feet when that good frame appears earlier.