Rick enjoyed the ship yard and was interested to see these propeller blades in reserve. Apparently, these blades can be used to replace damaged blades on the large freighters.
While driving along the canal, we saw several of these machines and at first, we didn't know what they were. After watching them for a short time, however, we determined that these were cutting weeds from the canal bottom. They really cut through the weeds in a hurry and harvested them at the same time.