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16.8.9 Each navigation light fixture shall bear the following information in an accessible location:
16.8.9.2 designation of the proper replacement lamp
Using a light source other than specified by the lamp assembly designer is against the intent of the
standard.
An LED array with the base of a bulb designed for retrofit into an existing incandescent lamp asse
bly is a financially attractive option to the DIY (do-it-yourself) boat owner. They don’t have to repl
the assembly with a, potentially more expensive, complete LED lamp assembly. This gives the owne
the low power consumption benefits of LEDs without the additional wiring and possibly fiberglass
work of installing a different lamp assembly. Regardless of the claims of the LED replacement bulb
packaging, the existing lamp assembly’s optics were not designed for the LED’s unique light pat-
tern. Even if the retrofitted LED physically fits and illuminates, it may put too much or not enough
light where it is both needed and legally required for a navigation light to communicate with other
boats correctly. Additionally, as the boat rotates relative to the viewer, the LED retrofit may create
blotchy light pattern, giving a flashing effect at distance. The retrofitted LED and existing lamp as-
sembly were not color tested together by the lamp assembly manufacturer, something that is specifi
in detail in A16. Nor were they heat tested, which is concern for LEDs as their light output and life
decrease with heat. An LED retrofitted into an incandescent system has more points of failure than
bulb or a properly designed LED system.
Courtesy, exterior, and cabin lights are not optically regulated by ABYC except they cannot visuall
obstruct the navigation lights. In these applications the LED retrofits may be acceptable provided
they meet ABYC’s electrical standards. -
dcasali@abycinc.org
 
Substituting LEDs In Navigation Lights 
A16 “Electric Navigation Lights” states: 
By Dante Casali
 
Even without the step to batteries, hybrid would require: internal combustion engine driving a generator, the generator
through cables driving an electric motor, the electric motor driving the prop. A conventional marine installation, by con-
trast, just has the main engine directly diving the prop through single shaft. The normal reduction-gear loses about 1.5%
power along the way. Even including the reduction gear, a good direct-shaft standard propulsion system will deliver 95%
96% of engine brake horsepower to the propeller (shaft horsepower—SHP). A hybrid diesel/electric- or gasoline/electric-
drive installation will find it difficult to deliver even a mere 88% of engine brake horsepower to the propeller.
Interestingly, diesel/electric drive is quite old in marine propulsion. The first such installations were used about a hundr
years ago. Diesel/electric is not “wrong” or “bad.” There are definitely instances where it makes sense, but they are not
installations where direct improvement in propulsion fuel economy is the goal. A typical example of an appropriate dies
electric propulsion system is in a large cruise ship. Here, the huge domestic electric loads are handled by several large
erators (as well as a number of smaller auxiliary ones). These same generators can be switched—in various combinatio
depending on speed and sea state—to drive the main-propulsion electric motors. In this way, the domestic loads and th
propulsion loads can be intelligently shared among the generators for maximum overall efficiency factoring in both the
domestic demands and propulsion demands
combined
.
Hybrids Are Not The Answer
(continued from page 7)