Assertion: keel's advantage | /r/CapableOf | add in small boats
Facets:
Source sentences:
text: The advantage of water ballast is that the tanks can be emptied, reducing draft or the weight of the boat (e.g. for transport on ground) and water added back in (in small boats, simply by opening up the valves and letting the water flow in) after the boat is launched or cargo unloaded.