The subject of using a fine screen
external strainer in place of an internal strainer has come up. At my last haul out
I installed a Groco APHS series hull
strainer but left my internal strainer in place. I recently rebuilt my internal strainer and realized I hadn't cleaned it since I installed the fine mesh external strainer. There were a few tiny oysters in it. I think they had grown in the thru-hull when the boat sat for a period of time and broke loose when the engine
started again. I'm going to keep both for now but it sure would be nice to get rid of that big internal strainer.
Groco Perforated Hull Strainers (APHS series)