Stan Miller Yachts

1991 Viking 50 Convertible

  • 50 ft
  • Sport Fishing
  • Ventura, CA, US

Yacht price :



The Viking 50 Convertible is a heavily built, heavily armed, highly mobile water-borne tank.

Introduced as the successor to the 48 Convertible, long bastion in Viking's line of convertibles. Credit for her rough weather gutsiness can be given to her steeper forefoot and increased flare (compared to the 48') in the forward sections. Designers Bruce Wilson and Bill Healey also improved down-sea handling and reduced back-down wash by refining and reshaping the transom and corners adding a touch more lift here and reducing a bit of reverse chine there.

Chaser is a very nice example of a West Coast rigged tournament ready machine with Furuno Sonar, Tuna Tower, and only a few hundred hours since the engines were overhauled.


Basic Information

50 Convertible
Ventura, CA, US
Available for sale in U.S. waters:
Vessel Name:
Boat Type:
Sport Fishing
Hull Material:
Hull Type:
Hull Color:
Flag of Registry:

Dimensions & Weight

50 ft - 15.24 meter
50 ft 6 in - 15.39 meter
16 ft 4 in - 4.98 meter
Draft - max:
4 ft 9 in - 1.45 meter
Bridge Clearance:
Dry Weight:
58814 lbs


Detroit Diesel
Cruise Speed:
23 MPH - 19.99 KTS
Joystick Control:
Engine Type:
Drive Type:
Direct Drive
Fuel Type:
760 (Individual), 1520 (combined)
Max Speed:
26 MPH - 22.59 KTS

Tank Capacities

Fuel Tank:
805 gallons - 1 tank(s)
Fresh Water Tank:
208 gallons - 1 tank(s)
Holding Tank:


Total Cabins:
Total Berths:
Total Sleeps:
Total Heads:
Captains Cabin:
Crew Cabins:
Crew Berths:
Crew Sleeps:
Crew Heads:



Inside Equipment
Microwave oven - Sharp Carousel II
Battery charger - Lewco Silicon Diode
Electric head - Sealand Vacu Flush
Hot water - Lochinvar 19 gal
Fresh water maker - Vantage Marine Aqua Systems
Refrigerator - Kenmore Side By Side
Air conditioning - Cruisaire

Electrical Equipment
Generator - Onan 15 kw 4075 hours
Shore power inlet - Glendinning Cablemaster 50 amp 240V & 30 amp 120V


Very often, the life of a convertible sportfishing yacht is limited by her non-fishing owner to cruising from marina to marina with an occasional hop to the islands. Thus the cockpit of a cruising convertible is more likely to suffer damage from unremoved high heels than from a  swordfish, wahoo or marlin and bill marks on the side of the transom would be unheard of. That however, fishing boat that also happens to be a nicely appointed cruiser.

Entering the salon from the companionway cockpit door situated to starboard the generous beam is instantly present with a comfortable L-shaped settee to port and the galley forward also port side. The starboard side of the salon is occupied by the main electrical distribution panel and AV and stereo components. Opposite the galley forward on the starboard side is a L-shaped dinette with a 90's period correct acrylic table. Forward of the Dinette is the location of the flatscreen tv and additional storage cabinets. The galley sole is gloss varnished teak & holly and the countertops are granite. The residential sized side by side refrigerator and freezer are easily accessed and provide a divider between the galley and aft settee.

Moving forward and down four steps the port side guest cabin is furnished with two bunks over under configuration. The master stateroom is to starboard with its own private Vacu-flush head and shower. A very generous stateroom in the 50' range with excellent lighting and a single overhead deck hatch. Opposite the companionway is a generous pantry ideal for stocking supplies or a potential tackle locker room. Forward to port is the guest Vacu-flush head and shower. The forepeak is offered with a double berth to starboard and a single bunk above. 

  • Cruisair reverse cycle heat & air conditioning
  • Kenmore side by side refrigerator ice & water dispenser
  • Sharp Carousel microwave oven
  • Sealand Vacuflush freshwater heads
  • Bar Ocean clock & barometer
  • LED salon over head lighting
  • Princess 2 burner electric cooktop
  • In-sinkerator garbage disposal 

  • Northstar 6000i GPS Plotter
  • Datamarine DART 2490 multi
  • Furuno CH-250 Sonar
  • Furuno 1930 radar 36 mile
  • Furuno Color Sounder
  • Si-Tex 525 ADF VHF
  • ICOM IC-M127 VHF & ICOM IC-M527
  • Trimble Navigation Nav Trac GPS
  • SEA156 VHF/ FM Radiotelephone
  • Standard Horizon Hailer
  • ITT Jasco Spotlight
  • ICOM HM 985S 2 meter radio
  • Simrad AP 25& AP 26 (tower) autopilot
  • Danforth Constellation 6" compass
  • Sea Tel satellite television antennae
  • JVC XV-N50 DVD player
  • Xantech PA1235 12 channel power amplifier
  • Parasound TDQ-150 stereo tuner
  • Phone-com intercomPanasonic 32 flat screen TV

Additional Details
  • Solid fiberglass hull bottom with cored hull sides
  • 2.25" stainless steel propeller shafts
  • Dripless shaft seals (PYI)
  • Bronze 3 bladed propellers 28" x 32"
  • ZF Marine gearboxes 1.5/ 1 ratio
  • Bronze spade type rudders 13" x 21"
  • Bennett trim tabs
  • Freeman Marine watertight engine room hatch
  • Fireboy 1301 fire suppression system
  • Lakewood engine room fans
  • Air compressor 1 gallon below helm console
  • Jabsco oil change system
  • Neptune water meter
  • Amtrol water pressure accumulator tank
  • SVS battery bank monitor

Detroit Diesel 8V92TA

The 8V-92TA was the first marine engine to which the DDEC was applied. The diesel engine is an internal combustion power unit, in which the heat of fuel is converted into work in the cylinder of the engine.

In the diesel engine, air alone is compressed in the cylinder: then, after the air has been compressed, a charge of fuel is sprayed and ignition is accomplished by the heat of compression.

In the two-cycle engine, intake and exhaust take place during part of the compression and power strokes respectively. In contrast a four-cycle engine requires four piston strokes to complete an operating cycle: thus, during one half of its operation, the four-cycle engine functions merely as an air pump.

A blower is provided to force air into the cylinders for expelling the exhaust gases and to supply the cylinders with fresh air for combustion. The cylinder wall contains a row of ports which are above the piston when it is at the bottom of its stroke. These ports admit the air from the blower into the cylinder as soon as the rim of the piston uncovers the ports.

The unidirectional flow of air toward the exhaust valves produces a scavenging effect, leaving the cylinders full of clean air when the piston again covers the inlet ports.

As the piston continues on the upward stroke, the exhaust valves close and the charge of fresh air is subjected to compression.

Shortly before the piston reaches its highest position, the required amount of fuel is sprayed into the combustion chamber by the unit fuel injector. The intense heat generated during the high compression of the air ignites the fine fuel spray immediately. The combustion continues until the fuel injected has been burned.

The resulting pressure forces the piston downward on its power stroke. The exhaust valves are again opened when the piston is about half way down, allowing the burned gases to escape into the exhaust manifold. Shortly thereafter, the downward moving piston uncovers the inlet ports and the cylinder is again swept with clean scavenging air. This entire combustion cycle is completed in each cylinder for each revolution of the crankshaft, or in other words, in two strokes: hence, it is a "two stroke cycle".

The greatest advantage of the 2-cycle marine engines are the rate of acceleration, and the low level of vibration. Every down stroke of the piston is a power stroke, therefore there are twice as many firing impulses at any given time over a four-stroke engine. This enables the engine to adjust quicker to throttle position changes and along with the characteristics of the engine's torque curve, provides better acceleration. As the firing frequency is twice as high as a four stroke, the engine operates with less vibration. Because of this, transmission, torsional coupling and mount manufacturers in many cases are able to approve higher ratings for their products without any degradation in their durability.

Detroit Diesel marine engines are rated in both brake horsepower and shaft horsepower. Brake horsepower is the horsepower produced at the flywheel, while shaft horsepower is the horsepower available at the output flange of the transmission.Typically the shaft horsepower is 3% less than the BHP due to the parasitic losses in the transmission.

From the initial order engines are specified not only to be marine engines but also as port and starboard models. While both models are right hand rotation engines, they are configured to have inboard access by the operator. With a single turbocharged engine this also designates that the exhaust outlet will be outboard.

The following is a breakdown of the Detroit Diesel nomenclature:

Example: 8V-92TA

8 = 8 cylinders

V = configuration of cylinders

92 = 92 cubic inches per cylinder

T = Turbocharged

A = after-cooled


  • In 2014 both engines received major overhauls at roughly 3690 hours. Less than 200 hours have been accumulated since major overhaul (SMOH). The boat has now run a total of 3892 total hours since new.
  • Water-cooled exhaust manifolds, risers and turbos
  • Full bypass blower
  • 4-valve cylinder head (all exhaust)
  • Gear driven raw water pump
  • Closed crankcase vapor collector system

Detroit Diesel DDEC

In 1979 a major engineering development program was started to find a way, using all available technology, to significantly improve the efficiency, reliability and durability of Detroit Diesel Allison engines. In order to achieve the highest levels of efficiency, engineers realized that a micro processor would be required. This is due to the fact that there are limits and compromises in using only mechanically controlled components. With a micro processor on board, control of the combustion process throughout the entire operating range is possible. This is primarily the reason why the aircraft industry and the automotive industry have developed this computer controlled technology to the level which we are at today. There are very few of us who do not rely on this technology, knowingly or otherwise to get to work each day or even aid us in doing our work.

As Delco, with their automotive experience, had more knowledge on electronic engine controls than anyone else, Detroit Diesel Allison engineers began to work with them to develop an industrial grade version of their proven design. In 1985 the first DDEC engines were introduced and today there are over hundreds of thousands DDEC engines operating in numerous applications throughout the world. 

There are basically four major differences between an MUI (mechanically unit injected) engine and a DDEC engine. The difference being that the mechanical governor, the injector rack, fuel modulator and the mechanical unit injectors are all replaced with an ECM (electronic control module), sensors and electronic unit injectors.

The electronic unit injector is basically the heart of the system and was designed to be more reliable than the mechanical unit injector by simplifying the design. The most noticeable change is that the complex helically machined plunger is replaced by a simple, electronically controlled solenoid valve and straight plunger.

The movement of the valve is controlled by the electronic control module (ECM). The (ECM) receives input from sensors located on the engine that tell it what the operating conditions are. The sensors provide information on the vital signs of the engine, such as turbo boost, timing, oil and fuel temperature. The ECM processes this information and sends a signal to the electronic unit injector (EUI) as to how long the solenoid should keep the spill valve closed . In response to operating conditions, this signal varies both in duration and in injection timing referenced to the position of the piston in each cylinder.

With the ability to vary injection timing, both acceleration smoke and cold smoke are significantly reduced while providing increased torque during acceleration for improved performance. As all of the fuel is completely used in the combustion process, excess fuel is not present to "wash down" cylinders of lubricating oil. This benefit alone leads to reduced engine wear.

Marine DDEC was first introduced during the Miami Boat Show in 1990. In order for boat owners and captains alike to be able to maximize the features and benefits of DDEC, a complete controls and display system was developed and introduced along with the engine.

For the throttle and transmission controls, there were two different styles available. One is a geometrically designed control and the other begin a new slim line series which was introduced in September of 1992. Both were available in either brushed stainless steel or black and are completely waterproof. This boat utilizes both styles.


Brief Detroit Diesel History

Beginning in 1986 Detroit Diesel Allison Division began shipping pleasure craft marine engines which are commonly referred to as "forward plan" engines. Forward plan refers to engines that were specifically designed and built to be used primarily for pleasure craft installations. These engines feature complete heat exchanger cooling systems, water cooled exhaust manifolds, risers and turbos and transmissions. In addition, these engines have undergone numerous internal changes to improve their efficiency.

In 1991 Detroit Diesel was building complete marine engines from 150 BHP to 2400 BHP. These factory configured and manufactured engines provide commonality of parts and are supported by trained personnel throughout the world.

Prior to 1986, Detroit Diesel Allison only built complete marine engines based on elected models. DDA distributors, recognizing the benefits of the 2-cycle engine for boats, took it upon themselves to take a base engine and marinize it. As the demand for higher horsepower engines increased, distributors responded by re-engineering marine components on existing factory marine models to increase the ratings. Many of the distributors (example: Johnson & Towers J&T, Covington, Stewart & Stevenson) did an exceptional marination, which enabled DDA to become the recognized leaders in marine propulsion.

When Roger Penske took over as CEO for DDC, it was recognized that many of these distributor modified engines were operating in waters world wide. It became apparent that customers were becoming confused as to the different ratings, configurations and warranties. Therefore the decision was made based on the engineering resources and experience gained through the distributors to concentrate their efforts on sales and product support. 

Cockpit & Deck Equipment
  • Pipewelders aluminum tuna tower
  • Fiberglass swim platform
  • Transom door
  • Ideal electric windlass
  • Bruce anchor
  • 144 sq. ft. cockpit
  • Built in freezer
  • Built in Prep station with sink
  • Built in tackle cabinet
  • Padded coamings
  • 5 flush mounted rod holders
  • Cockpit awning
  • Rupp aluminum outriggers & center rigger
  • Split island cockpit bait tank & bow tank
  • Fresh & salt water wash down

Estimated Performance

800 RPM 8 knots 8 GPH

1080 RPM 10 knots 16 GPH

1200 RPM 10.6 knots 22 GPH

1300 RPM 11.1 knots 26 GPH

1400 RPM 11.8 knots 30 GPH

1500 RPM 13 knots 36 GPH

1600 RPM 14.6 knots 43 GPH

1700 RPM 16.5 knots 48 GPH

1800 RPM 18 knots 53 GPH

1900 RPM 19.2 knots 60 GPH

2000 RPM 20.4 knots 66 GPH

2100 RPM 21.5 knots 70 GPH

2250 RPM 22.6 knots 80 GPH

The estimated performance fuel consumption cannot be guaranteed due to loads and sea conditions.



Presented by :

Ian McGhie

View Profile
19 Listing(s)

Our Locations :

Featured Yacht :

Disclaimer: The Company offers the details of this vessel in good faith but cannot guarantee or warrant the accuracy of this information nor warrant the condition of the vessel. A buyer should instruct his/her agents, or his/her surveyors, to instigate such details as the buyer desires validated. This vessel is offered subject to prior sale, price change, or withdrawal without notice.