Differences in cinematic when dragging the time bar or playing the sequence

Hi there,

I'm trying to create a cinematic of a boat moving through the ocean.
I have an ocean animated through an animclip inserted in timeline.
The problem is when I try to move the boat so it matches the ocean surface, the results are different when I drag the Timeline bar (frame by frame) to reposition the boat or when I press play, see picture:


Note the boat is floating normally when dragging the time bar, but it is sinked when playing the animation on the exact same frame. This makes it impossible for me to keep the boat "floating" over the surface. Any idea what could be the issue?

Here it is a far plane of the same scene so you get an idea of the cinematic I'm trying to create (note the issue is not visible here because the boat is further away):

Thanks