Animations are being cut out of the classic tween

Video included.

Basically, I made an animation of the boat bobbing up and down and water lapping at it's sides. That works great.

But when I try to tween the boat to move across the screen, the bobbing and lapping animations don't play; the both simply moves. The boat starts to bob on the last keyframe.

I'm new to the program, so I'm sure there's something simple I missed, but I was following a tutorial and have retraced my last several steps. I'm wondering if there isn't something about the boat animation itself that's not set up right, causing this issue.