Camera not focusing at 30x zoom

[SlicePi]

S24FE , stock camera app

Im on a cruise ship, 15th floor (150'? high).

There's dolphins near the horizon (5miles away?) but the phone won't focus at 30x zoom.

I tried pressing at the horizon where the sky meets the water. Nope.

I tried long press where the Sky meets the water and the white circle turns yellow. Nope.

How to get my phone to focus at 30x zoom?

[meself]

Gets tricky at 30x zoom