decide on a boat

What does "decide on a boat" mean?

Dolly,

Dolly: "Oh, I like that red one! No, I like that blue one! Boy, I'm having a hard time deciding on a car!"

Bob: "Boy, you couldn't decide on a car, even if your life depended on it!"

It probably means "choose a boat", but it could be interpreted as "make a decision while one is on a boat". :)

I read some of these messages and I wonder if I am on Mars...

Dolly: "I just can't decide what to make for dinner."
Bob: "I know. Let's decide on a boat. The calm waves of the sea always ease my decision-making process."

It must be a gravy boat in the last example...

I've ordered a "boat" before at Japanese restaurants.