Plug-in solar panel option

[CDK]

If you succeed in overcharging your battery with the panel you've described, you can probably walk on water too.
I have a 16 Wp panel and 240 Ah of batteries, live in the sunniest part of Europe, yet the charge is only just sufficient to compensate for self-discharge, the bilge pump and 8 mA for the alarm system.

In the past, I had a bilge pump with only a float switch: the panel could not cope with the power consumption. Pump and switch kept each other busy for hours because the back-flow of the water still in the hose was enough to switch the pump back on again.
So I added an rc-delay and a transistor that keeps the pump going for approx. 10 seconds after the float breaks the circuit.

[Ratch]

Hi CDK

We started discussing overcharging the battery when Stuft decided to get a new panel.

As things stand now:
Battery size - unknown
Panel size - unknown (was an old 5w)
Pump size - 1.9amp@12v (googled make)
Pump run time - guessing between 5-10min per day.
Mooring location - Sydney or around there

[CDK]

Thanks Ratch, I missed that. My 1200 m. telephone cable, hanging on poles under the power cable makes the internet very slow sometimes.
Stuft mentioned 350 Amps for the battery: I guess he meant cranking current, so the capacity will be approx. 50 Ah.