dc wiring

[AnchorageGuy]

Chris, You need to do a lot of research before you dive in to a project like rewiring. The size wire you need depends on variables such as the load it will carry and the distance run from the power source, etc. rather than the bulb size and cost at the chandlery. By all means shop for the best price for the "required size" for each given run and not just the best price for whatever size wire they have available. A misstep in this project can and has burnt a boat to the waterline. That does make your neighbors very nervous. Get Calder's book and/or the 12 Volt Bible and do your wiring layout well in advance with good forethought and working knowledge. If some of this stuff costs a bit there is a reason for that. Good Luck

[Boracay]

My reading of the the table in Amazon.com: Boatowner's Mechanical and Electrical Manual: Books: Nigel Calder has 4mm cross section area corresponding to between 12 and 11 gauge wire.
His table for length with a 3% voltage drop suggests that a 30 foot run is acceptable for a 5 amp device (with a 10% voltage drop the distance jumps to 130 feet) if I have read it correctly.
I have assumed that a 2 amp device would have no problems.
I was curious to see if there were any problems in using this wire as it is cheap.