Our grounding last summer brought up some deficiencies (I know, an understatement) in my skills and Bolero's outfitting. So I decided that I wanted to add a depth sounder and navigation lights and an a small electrical system to support them.
I don't expect that either of these two additions would have prevented our grounding, as many boats with grander systems than this find a way to ground, but my hope is that they will provide additional information that will help engage my brain in a way that promotes safer choices.
My first dilemma was finding a location for the panel. After some thought I chose to incorporate a panel into the box that Tim built to cover up the chainplate knees. By positioning components just so I was able to fit them between the chainplate knees.

After many, many mockups and much taping I install the solar charge controller, the switch panel and a voltage and amperage gauge.

And then I installed the battery on the back of the panel and installed the panel in the boat.

Then I got set up and started running wires.

I don't seem to have any photos of the various steps from here, but here is the finished and installed panel.
I still need to located and run the wire for our handheld VHS.


I was forced to decide were to run exposed wires and which beautiful piece of wood would have holes drilled in them. But after some initial pain my breathing become normal again.
This system allows us to charge the on-board battery with the 5 watt (1/3 amp) solar panel while we are on the mooring. During sailing we fold up and store the solar panel and run the GPS, depth sounder transponder, VHS and, if needed, the navigation lights off the on-board battery. In the event that the on-board battery becomes low, I can run the GPS and VHS from their own batteries and save the on-board battery for the depth tranducer and the navigation lights.
The integration with the Garmin 276C GPS is actually quite good. In addition to displaying the depth from the transducer is also displays the system voltage (which I now include in our log). I added this information to the map page so I can keep abreast of the present state of the on board battery.
Once I had the panel installed and wired I installed a set of Perko chrome over brass navigation lights. I agonized over the types and locations of these lights for some time but eventually I just dove in and installed my best choice.

I am not overjoyed with the looks of these navigation lights on Bolero but they are installed and work. I am currently working on replacing the 300 ma bulbs with acceptable leds. My first attempt missed the mark but I am still looking. I could only run the incandescent bulbs for a short time with my small electrical system.
Here is a summary of our electrical loads, assuming I get my led bulb change to work.

This chart is missing a few things since I don't include the voltage and amperage gauges which draw approximately 30 ma each. In addition the lighted panel switches also draw about 30 ma.
In real life use I expect the charging and discharging to be more complex as initially the on board battery will top off the charge for the GPS and the VHS and only then begin supplying the running amperage for these components. Also the percent daily use will constantly change as well.
All that said, I am cautiously optimistic that this system will supply Bolero with all the modern conveniences normally taken for granted on other boats :).
Cheers,
Bill
As a long footnote, here is a list of the components that I used.
LiFePO4 Battery: 12.8V 6.8Ah (87Wh, 25A rate)

Dimensions: 4.9" x 2.6" x 3.1"
Weight: 2.2 lbs
I setup the back of the panel to accept two of these batteries should the need for expansion arise.
Solar / DC Charge Controller (120W, 10A Rate ) for 12V SLA or LFP Battery
The recommended solar charge controller for the LiFePO4 batteries.
Airmar P79 Smart Depth Transducer
The main reason for this project was adding some sort of depth gauge to Bolero. After a bit of research I found that I could add an Airmar P79 NMEA0183 in hull intelligent sender and feed the output to our Garmin 276C portable chart plotter. Of course this "smart" transducer cost more than a stand alone depth gauge.

Currently it is mounted using toilet bowl wax just forward of the mast and is working well. It sends the NMEA string DPT (Depth Below Transducer) to our Garmin 276C which is then displayed on the map page.