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Berkeley Jet Drive

Jet Drive's are Simple
Basically a jet drive is a water pump, which is driven by a conventional automotive engine that has been specially prepared for marine use. The engine is mounted within the hull and connected directly to the pump. There is no clutch or gear box.

The jet receives water through an intake grate in the bottom of the boat, and ejects the flow beyond the transom and through a steerable nozzle. The pump impeller, injecting the water, creates an equal force in the opposite direction which propels the boat forward. Steering is done by swinging the nozzle and rudder right or left, as desired.

The boat's attitude can be controlled by pointing the nozzle up or down within a controlled range on models with underway trim.

Reverse is accomplished by lowering a reverse gate across the outflow, diverting the jet stream forward, beneath the hull. Lowering the reverse gate when the boat is going forward, can stop the boat virtually within its own length. (Stopping should be done carefully to prevent passengers or free objects from being tossed forward.) There is no extra strain on the engine or the Jet-Drive when going from forward to reverse. The drive system can't detect the change; its rotation and load are not affected.

SAFER THAN A PROP
A propeller is a hazard to swimmers and skiers, and a matter of constant concern to the skipper. Injuries and fatalities to persons struck by propellers are regularly recorded by the U.S. Coast Guard. Moreover, it's easy to bend a prop in shallow waters and lose control, which hazards the boat and its passengers in swift currents or rough water. Also, if the propeller or leg strikes a rock with considerable force, the resultant damage most likely will extend to the lower leg, and really disable the boat. The safety and dependability of Jet-Drives really count!

EASY TO MAINTAIN
There are few parts in a jet drive. The direct-drive shaft has a thrust and tail bearing. The impeller is fixed to the shaft and completely enclosed. The intake grate screens out most trash, but if tough weeds, string or a small rope pass the grate, and remain in the impeller, these are easily removed through a hand hole which is normally covered.

With no gears and so few parts, overhaul of a jet drive may not be necessary for several years, or hundreds of hours of use. Parts are largely interchangeable and readily available. Access is simple and there's a minimum of downtime.

The engine is a heavy-duty automotive V-8, expertly modified for marine use. Maintenance is much the same as you would expect with a car.

GETS SKIERS UP FASTER
Because a jet can develop full drawbar thrust even if anchored or secured, it picks up skiers as quickly as their muscles will allow. The boat doesn't need to be moving before the jet can achieve full thrust.

SAVES ON GAS
Jet-Drive compares favorably with other types of propulsion on fuel consumption. Any engine uses excessive gas when pushed toward maximum RPM. At skiing speed a large V-8 can compare very favorably on fuel costs for a day of cruising, skiing and picnicking. Using the 12J, as an example: With RPM reduced to 70% of maximum Fuel needed is reduced to only 32% of maximum While speed is maintained at 66% of maximum. Thus at two-thirds full speed, fuel use is cut to less than one-third, resulting in twice as many miles traveled per gallon. Since jets use ordinary automotive grade gasoline without expensive mixing with oil, by seldom exceeding 50 MPH you can have a day's fun for little, if any, greater cost than running a smaller I/O or outboard.

COSTS LESS INITIALLY
Today a Berkeley Jet-Drive and 320 HP V-8 engine costs up to $7,000 less than a smaller block, conventional I/O with power train and prop. So a ski-runabout with Jet-Drive, because of its simplicity, actually costs less to buy while offering greater action, dependability, performance, and safety.

HANDLES DIFFERENTLY
A jet handles quite differently than the traditional prop and rudder. What makes a jet different, makes it better! It doesn't depend upon hull movement to attain full power. A prop unloads as forward speed is obtained, which lets the engine rev to full power that is only available at full boat speed. With a jet, you hit the throttle and take off right now, with full power. When you reverse a jet drive, you reverse right now. When you turn, the jet, plus the rudder, swing you around in a super-tight circle.

You can move a jet boat sideways into tight docking situations by switching from forward to reverse while coordinating the steering.

HAS HIGHER RESALE VALUE
Because of its low maintenance cost, long life, and enviable performance, Berkeley Jet-Drive owners, when they decide to "trade up" often realize almost as much as they paid for their boat years earlier.

Berkeley jet-drive offers more than 40 years of experience with pumps

Berkeley has been manufacturing pumps of many kinds since 1937. The Berkeley Jet-Drive was introduced in 1960, and many thousands have been supplied to the boating public since then.

Today Berkeley offers three 12J drives, each a little different but incorporating essentially the same basic features and using, where possible, many of the same parts for interchangeability. Improvements are made only after ample testing and extensive trial.

During the first 20 years, many brands of jet drives have come and gone. Some have been available for a year or two... some longer... some shorter. Berkeley remains the favorite year after year, and probably has supplied well over 80% of the thousands of units in use today. During these two decades, Berkeley has held every speed record set by jets. It was first to break the "100 MPH barrier: Its most recent top speed was clocked at 146± MPH. We cite this simply as an indication of the experience, durability and leadership behind the Berkeley Jet-Drive nameplate.