Last week, a bird-watching trip with two friends, Fran and Ranjit, and 120 other birders started with a 35 mph boat trip from Port Clinton, Ohio, near Sandusky, across Lake Erie to Point Pelee Provincal Park in Ontario, Canada.
Since my exposure to boating was limited to sailing the discontinued sunfish and paddling a fiberglass canoe, the speed, smooth ride and relative quiet motors were astonishing. When we disembarked in Canada, I noticed for the first time our boat was a catamaran design with double hulls. Later, I inquired about specifications of this boat, one of four in the Jet-Express fleet. The boat has a capacity or 250 people, weighs close to 60 tons and is powered by Caterpillar Diesel engines in each hull, generating a total of 2,200 horsepower. Propulsion is provided by two Rolls Royce FF 550 waterjets. The familiar jet ski seen on local lakes is propelled by a waterjet. Therefore, the commercial boat we traveled on, also powered by a waterjet, was a huge jet ski.
The waterjet mechanism of propulsion eliminates a propeller. It functions when water flows into a portal on the bottom of the boat hull where it enters a pump powered by a motor. Water is forced through a nozzle under high pressure creating a jet-like propulsion, pushing the boat forward. Steering is controlled by plates adjacent to the nozzle which are moved into the path of the waterjet stream to redirect the fast moving water and turn the boat left or right, known nautically as port and starboard.
This ocean and lake-worthy boat with double hulls is propelled by waterjets just like the personal wartercraft known as a jet ski.
Photo by Robert M. Ungerer
Even though I served two years in the U.S. Navy, I still think of a boat steering to the left or right. The steering mechanism is analogous to redirecting water from a garden hose with a thumb. To back up, the plates move in such a way to direct the waterjet stream 180 degrees in the opposite direction or forward, slowing and eventually reversing the boat's direction. The absence of a propeller permits shallow water operation and creates faster water speeds. The military utilizes waterjet propulsion in submarines since the sonar signal from a propeller is eliminated, thus making enemy detection of submarines more difficult. Disadvantages of waterjet propulsion include greater expense than propeller drives and water inflow in the hull, which can be clogged by weeds and debris.
The use of the double hull style of boat, now called a catamaran, became commercially available for pleasure power boating in the later half of the 20th century. Large Olympic and international sailing competition accepted the catamaran hull when the amazing speed and stability of the catamaran hull was recognized. Two slender hulls produce less drag in water than a single hull of the same weight. Stability provided by two separated hull in rough turbulent water lessens the chance for capsizing.
Ancient civilizations in Polynesia recognized the benefits of double hulls 2,500 years ago. Archeological evidence revealed the existence of double canoes 60-70 feet in length for 50-70 passengers, crew and cargo.
While this article presents a discussion of waterjet propulsion and is not intended to be an advertisement for the Jet-Express, I was pleased to know the boats in their fleet were American made in Somerset, Mass., by Gladding-Hearn Shipbuilding, a Dulcos Corporation. The fleet was the first waterjet catamaran service and the fastest ferry in North America. While Jet-Express transports only passengers, another ferry service in Port Clinton, Ohio, transports passengers and automobiles. Both service the Lake Erie islands offshore from Sandusky, Ohio, including Put-in-Bay and Kelley's Island. These islands are popular destinations for summer night entertainment and day time lake activity. Ferry service is scheduled almost hourly from June until mid-September.
If you have time for a short vacation, a catamaran waterjet ride to the Lake Erie islands or to the birding hotspot on Point Pelee, Ontario, in early May will provide a thrilling ride whatever the weather.
By the way, the bird-watching trip produced my first time sightings of the Orchard Oriole and the golden-winged warbler.