Personal Flotation Devices (PFDs): A Canadian approved PFD is designed to keep you afloat in the water. PFDs were designed for use in recreational boating and are generally smaller, less bulky and more comfortable than lifejackets.
The Erie Canal, in New York state (shown below), was 360 mi (580 km) long, and connected New York with the Great Lakes via the Hudson River. Locks were built to overcome the 571-ft (174-m) difference between the level of the river and that of Lake Erie.
Locks on the Erie Canal. The present Erie Canal rises 566 feet from the Hudson River to Lake Erie through 35 locks. From tide-water level at Troy, the Erie Canal rises through a series of locks in the Mohawk Valley to an elevation of 420 feet above sea-level at the summit level at Rome.