Meaning of Cruising down
Are the following sentences correct?

We CRUISED DOWN 45 minutes before we got to Cozumel.
We were CRUISING DOWN by kayak when he told us our time was over.

Question

Meaning of Cruising down
Are the following sentences correct?

We CRUISED DOWN 45 minutes before we got to Cozumel. 
We were CRUISING DOWN by kayak when he told us our time was over.

Answer

In the first sentence, you would not use 'down'. We cruised FOR 45 minutes.....
The second sentence: we cruised down THE RIVER by kayak. You do have to add where you cruised down, or it does not make sense.

Answer

Personally, I feel like more context is needed, like which road or river you're cruising down. I think something like "This car was made for cruising down the 101 highway on a sunny day" sounds a little more natural.