domestic grid solar panel to charge 12v dc

I have an older timber cruiser, perminantly moored which requires intermittent use of a bilge pump. I have a few bilge pumps for reliability and backup, but the basic power system on the boat is powered by a single N70 12v battery. I currently have an older Solarex 40w panel which has lost capacity and needs replacement.
However, I do have some 190w x 48v domestic grid panels surplus after upgrading my home grid system and was wondering if I could use a transformer to drop the voltage or do I need a specialized controller?
Perhaps not possible at all...
I have reasonable 12v knowledge, but not up to date with full electronic and electrical jargon.
It seems silly to pay for a new 12v panel if I can convert a 48v panel at minimal cost
Thanks
However, I do have some 190w x 48v domestic grid panels surplus after upgrading my home grid system and was wondering if I could use a transformer to drop the voltage or do I need a specialized controller?
Perhaps not possible at all...
I have reasonable 12v knowledge, but not up to date with full electronic and electrical jargon.
It seems silly to pay for a new 12v panel if I can convert a 48v panel at minimal cost
Thanks
Comments
They are NOT inexpensive. Seems I heard recently of a couple other marine sealed charge controllers, but I would generally recomend a Midnite Solar Kid inverter.
https://www.solar-electric.com/midnite-solar-kid-marine-mppt-solar-charge-controller-black.html
Charge controllers are rated at output amperage, so you might want too use Midnites's string sizing tool to figure out how many panels you could put on it.
https://midnitesolar.com/sizingTool_kid/index.php
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,