I currently have two arrays of 4x20 watts each, one on each ama. They are wired series-parallel in two pairs on each side (2 panels in series, and the two pairs wired in parallel, both sides wired in parallel and diode isolated) so I have up to about 34+ volts (open circuit measurement) running back to a single MPPT charge controller. The controller converts the voltage to the appropriate voltages to charge the house bank based on its state, and also incorporates temperature sensing at the house bank. I achieve better efficiency by running the wiring from the panels at higher voltage (~34+ volts open circuit measurement) because the voltage drop in the wire is less significant and the effective charging rate is higher more hours per day than it would be if they were all in parallel at ~17 volts (open circuit measurement).

This shows my present setup x2 sides

I put this together in my basement to be added to my existing arrays. These are semi-rigid panels that have an unbreakable polycarbonate face. I bought 2 extra panels as spares when I initially installed the ones on the amas, but haven't needed them (yet) -- so I decided to put them to use and increase capacity. I used 1/2" King Starboard XL (lighter weight) as a backing, cut it to size on the table saw and used a router with 1/4" round-over bit to smooth the edges, and drilled for 1/4" stainless mounting bolts with Nylocks.

I installed a splashproof junction box on the underside. I will wire this extra panel pair in series also, and parallel them to the port/starboard arrays. The junction box will also contain a fuse holder and diode on the output of the connection to the rest of the system.

This image shows more of the underside. The rail mounts are positioned slightly offset so that the inboard overhang is reduced to 10.5". I wanted to find a compromise between balance and minimal intrusion.

I had a Magma bait table in the intended mounting position (next to the barbeque on the taffrail) that intrudes about 9" so I have experience to know I can live with this overhang. This assembly will replace the table, which I use for plates and utensils while cooking. I don't fish anymore. I don't think it will be an issue if these panels double as a convenience table once in a while at the dinner hour.