Final answer:
Boats over 16 feet in length must carry visual distress signals on certain navigable waters for safety reasons, regulated by the USCG. Trailered boats have been identified as vectors for the spread of aquatic invasive species, necessitating cleaning and rinsing practices to protect ecosystems.
Step-by-step explanation:
Boats are required to carry visual distress signals on coastal waters, the Great Lakes, territorial seas, and connected bodies of water that are navigable to the sea for vessels over 16 feet in length, as regulated by the United States Coast Guard (USCG). This is part of marine safety regulations to ensure boaters can signal for help in case of an emergency. Distress signals are important for boater safety and can include flares, flags, smoke signals, or electronic beacons depending on the type of waters and the visibility conditions.
Concerning environmental impacts, recreational boats — specifically trailered boats — have been studied as vectors for the spread of aquatic invasive species. Measures to prevent such spread include cleaning the hull, propeller, anchor, and trailer of all visible plants, animals, mud, and debris, and draining and rinsing live wells, bilge areas, and gear after exiting the water. These practices help protect the aquatic ecosystems, like Maryland's, from invasive species such as Zebra Mussel larvae and Spiny Waterflea.