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Boat Type: 4 Passenger, Vee-Pad Runabout
Length: 15'
Beam: 89"
Transom Height: 23" 1977
and prior, 21-3/4" after.
Recommended HP: 50 - 120
Seating: 2 Buckets and Rear Bench (1978 and older models had back to back front seats and no rear bench)
Approximate Weight: 570 lbs




Pictured here is a special edition 1976 Viper with a factory gelcoat scheme in honor of the nation's Bicentennial.  It is not known exactly how many were produced with this design, but a good guess might be around 20 or 30.  HydroStream highlighted one of these at boat shows, most notably the huge NY Boat Show held in the NYC Coliseum.  The Viper was the only model with this scheme.  Owners of boat pictured: David and Lisa Ladd.




The Viper was developed from 1971 - 1972.  It evolved from the highly successful Ventura model.  In Pipkorn's own words, "we took the Ventura, bobbed off a couple of feet from the nose, and lopped off the rear corners to get the boat to conform to Class E sport boat racing."  It obviously worked...Pipkorn took the 1977 World Championship in Class E sport boat racing.  The deck designViper4.jpg (25319 bytes) got a makeover too. Howard's brother, an artist, was impressed by the design of an old YF102A_DeltaDaggerairplane: the Delta Dagger.  He sketched up a concept design which was influenced by the flared wings of the Delta.  Taking it one step further, Pipkorn utilized a concave shape in the bow area which not only looked good, but also added strength and continued the tremendously strong hull design.  "I wanted to create a style that was recognizable from across the lake.  With one look I wanted you to know that it was a HydroStream," Pipkorn said.  I don't think there is any question that Pipkorn achieved that!  You can literally identify a HydroStream from a mile away - in looks as well as the way it flies.

The Viper Concept Sketch

In 1975, the Viper hull underwent some design changes.  Prior to '75, the splashwell area had a different configuration, the pad did not have the usual hook (actually a wedge) in the back, there was no flotation, and the "wing"/chine area had a narrower profile. Unofficially it was known as a Viper I prior to '75, and the Viper II after that. See the Vector model page for more discussion on the design change and the hook.



The Viper will seat 4 adults comfortably.  Storage is under the deck and under the front seat.  It is not a roomy boat.  The boat handles the rougher water at low speeds surprisingly well.

With an inline six for power the Viper will run in the mid to upperViper1.jpg (91591 bytes) 60's.  The acceleration is fair with a 115, but you can trim it to the moon and feel very safe and very high.  One drawback to the Viper is its ability to handle waves or rough water at speed.  If you spend a lot of time behind the wheel you gain a little more confidence crossing wakes, but it almost always feels like impending doom!  Another drawback to the Viper is that it sits low to the water at the transom (even with an inline).  This causes the boat to take on water coming off plane or when anchored.  With a V-6 you have to come off plane slowly or you will swamp the boat.

With a V-6 for power this little boat becomes a rocket.  It planes much quicker, needs less trim to fly, and has awesome acceleration.  The boat feels pretty stable up to 80-85 if you are an experienced pilot.  After that it feels really light.

The Viper is not a very good weight-carrying hull.  It has a tendency to porpoise with weight in the boat over 25 mph and until it gets on the pad.  With the pad filled in, it makes the porpoise much better and a big blade chopper helps more.  For top speed, a Cleaver prop works well as it helps reduce the harsh reality of blowover which is one of the dangers we have to live with due to Pipkorn's "Delta-V" design.  A healthy Merc 2.5 200 HP will see speeds in the low 90's.  Those with aspirations of 100+ mph: forget it...blowover no longer becomes a question of if, but more like when....

All in all, the Viper is an excellent hot rod.  It can do it all: tow skiers, take up to 4 adults cruising, and scare the pants off of you with its awesome speed and bow-light feeling.


75 Viper - Boat House Bulletin (Mercury Marine)


74Viper1.jpg (40425 bytes)

74Viper2.jpg (23918 bytes)

Pre-'75 Design


ViperBottom1.jpg (81272 bytes) ViperBottom2.jpg (85587 bytes) ViperBottom3.jpg (136713 bytes)
ViperBottom4.jpg (111877 bytes) ViperBottom5.jpg (142288 bytes) ViperBottom8.jpg (141823 bytes) ViperBottom9.jpg (129495 bytes)
Pictures of the Viper II hull.  This one has been blueprinted and had the pad filled and straightened.  Note the sharp edges on the strakes and the trailing edges.  Expert work was done by Chris Brabender (Boatmender) - see Chris's latest Viper project ("Saved from the Junk Pile") under Feature Articles.  For pictures of a Viper hull with the original wedge design in the rear of the pad, see the Vector page.


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