Wiring my first boat

[Captain Hook]

I own a 25" Coronado that was submerged for 5 months... I'm rebuilding it and an om the wiring phase. This is my first boat so I have no idea what I'm doing, but it looks pretty simple. The switches seem okay and the wiring doesn't look very corroded. I have a batterry, the mast is currently down but the wiring is there for all the Navigation lights, radio, etc. Any suggestions or links to diagrams for reference?

[hoytedow]

I would replace all wiring as salt intrusion creeps into the insulation ruining the wire and creating possible ignition source.

[Ike]

I agree. Replace all the wiring. After that long under water you have no way of knowing how deeply the water penetrated the insulation. It's not worth the hassle and risk trying to save a little by not replacing it. The #1 cause of boat fires is electrical. Do it right. By the way see, http://newboatbuilders.com/pages/electricity1.html for starters, because if you don't know what you are doing wiring a boat you can get into real trouble very quickly.

[Stumble]

I would also recommend replacing the switches. Even if they look ok electrical components HATE water, and hate salt water even more. You could likely save a few bucks by skimping on the new stuff but somewhere down the road I promise you it will come back to haunt you in a big way.

However what you can do is use the existing wires switches, and distribution blocks as a guide to show you how it should be done. Assuming it is original of course.

[Captain Hook]

Thanx alot you guys, I'm definately going to buy a spool of marine grade wire and replace everything this weekend. The switches don't look so great either, but the switchboard looks fine. Also getting a 24volt deep cycle, an inverter and very possibly offshore power cord as well. If I'm not mistaken I can set it up to where I can charge the battery while running equipment when plugged in. Getting a little Evinrude for it too.

[hoytedow]

Color coding helps understand the wiring harness.

[Stumble]

Not that there arn't reasons to use 24V on a boat, but most of them don't really apply in a small boat like this. I would stick with the standard 12V system to be honest.

As for tool use from inverters... you can do it if the inverter is big enough, but most of the small ones won't be. If you have the option of just plugging them into shore power or a home circuit that is usually the better option. Most US supplied shore power is 110V at 15, 30, or 50 amps. All of which can take a standard extension cord plug with a $30 adaptor. This would probably be the better route.

[finnracing]

Excuse the ignorance gents. What length of boat would you consider installing a 24vdc system rather than 12vdc?

[marshmat]

It's not size so much as systems complexity that makes 24V worthwhile. If you have a big power windlass, a bow thruster, powered winches, air conditioners and a high house load, 24V is probably worth considering. If you don't have a lot of big, amp-sucking motors on board, 12V is simpler and probably cheaper.

As far as the OP's situation goes, the only real option is to rip out all the old wiring and start from scratch. You might like to use the old system as a guide, but put the new one together with good tinned, stranded copper wire, proper terminal blocks and switches, and colour coded appropriately. No electrical component that's spent five months in salt water is trustworthy.

[Ike]

I agree with Marshmat. It's the equipment you have and the complexity of the system that determines whether you use 12V, 24V, 48v or 110V. The size of the boat only comes into it, in that most smaller vessels just don't have a lot of heavy duty electrical equipment.

[Stumble]

Finn,

By example, my 54' cruising sailboat probably should have had 24V on some systems, but was done in all 12V. My 58' powerboat is also all 12V. I raced on a 70' sailboat all 12V...

The above posts are correct that it is really the complexity that matters not the leingth, but in practice I wouldn't really consider 24V until you the boats hits around 40'.

[gonzo]

That's a great sailing boat. I cruised mine from the Great Lakes to the Gulf of Mexico and the southern Caribbean. There shouldn't be a lot of wiring. Cabin lights, running&compass lights, anchor light, instruments if you have them.

[hoytedow]

And of course you run the wires in pairs to eliminate the introduction of magnetic compass deviation.