ABYC Standards 

The American Boat and Yacht Council is an industry based body which publishes a set of voluntary standards for all aspects of boat design and construction. The "Standards and Recommended Practices for Small Craft" is the industry bible for surveyors, boat builders and repairers. ABYC also also offers certification for professionals working in various fields. Technical questions from boat owners as well as from professionals are welcomed at the ABYC offices. Individual standards are available for purchase online for $65 each. Recommended for Electrical Systems is E.11 AC & DC ELECTRICAL SYSTEMS ON BOATS  Also available is the ABYC digest of USCG standards.  This article from Blue Sea Systems called ABYC Explained is helpful to understand the scope of their work.

US Coast Guard Standards

Coast Guard standards are available free online. However, because they are lengthy I recommend the ABYC digests of the various standards.  The actual standards can be found on the Government Publications Office website and start with 46 CFR 110 General provisions  This Article USCG Vessel Inspections Program is helpful in understanding what is covered.

UL Standards

At the time of writing there are 23 UL Standard relating to Marine applications, the list can be seen on the website www.ul.com  This article called UL Designations Explained is helpful in understanding what is covered.

Wire Size, Color, Specifications

AC wiring color codes

ConductorUS 115v ACUS 230v ACEurope 240v AC
GroundGreenGreenGreen and yellow
NeutralWhiteWhiteLight blue
Hot Red 





Yellow w/red stripe (YR)Starting circuit Starting switch to solenoid 
Brown/yellow stripe (BY) or
Yellow (Y) - see note
Bilge blowersFuse or switch to blowers 
Dark gray (Gy)Navigation lights
Fuse or switch to lights
Tachometer sender to gauge 
Brown (Br) Generator armature 
Alternator charge light
Generator armature to regulator 
Auxiliary terminal to light to regulator
Fuse or switch to pumps 
Orange (O) Accessory feed Ammeter to alternator or generator output and accessory fuses or switches. 
Distribution panel to accessory switch 
Purple (Pu) Ignition 
Instrument feed
Ignition switch to coil and electrical instruments. 
  Distribution panel to electric instruments 
Dark blue Cabin and instrument lights Fuse or switch to lights 
Light blue (Lt Bl) Oil pressure Oil pressure sender to gauge 
Tan Water temperature Water temperature sender to gauge 
Pink (Pk) Fuel gauge Fuel gauge sender to gauge 
Green/stripe (G/x)
(Except G/Y) 
Tilt down and/or trim in 
Tilt and/or trim circuits 
Tilt and/or trim circuits 
Blue/stripe (Bl/x) Tilt up and/or trim out 
Tilt and/or trim circuits 
Tilt and/or trim circuits 

Please note that striped wire is normally only available to special order with a minimum quantity required.  This means that it is really only possible to use then when building production boats and if you are dealing with a one off project it will not be a viable option.

Electrical Formulas

Ohms law: Volts = Amps x Resistance 

DC Power: Watts = Volts x Amps 

Voltage Drop in DC circuits: CM = 10.75 X x L / E 
Where CM is cross section of wire in circular mils 
I is the current in Amps 
L is the round trip in feet
E is the voltage drop in volts

Compendium of Electrical Formulas - more than you could ever imagine.

Other subjects of interest

IP Protection Explained
Circular Mils Explained 
CE explained