Engine Overheating-Restricted raw water
I searched for this so hope it is not duplication. This is a SIMPLE maintenance issue, but I often find sailors who don't know about simple problems. I have a 2008 Catalina 309 in St Pete, Fl. This week a member was using the boat when the overheat alarm came on. He stopped the engine (not sure how long) then cleaned the strainer of a bundle of sea grass. Started the engine, but after awhile it overheated again. Got it to a dock, tried the next day. Again overheated in about 20 minutes. Turns out a Mangrove pod had entered the raw water system and lodged in the line between the thru hull and strainer. I could feel it with the strainer removed. When I opened the thru hull, no water! I removed the hose clamps, remove the hose and removed the pod and sea grass behind it. I also replace the impeller and found no damage or lost vanes (yea!). Key: 1)Watch water temp when motoring, 2)after clearing debris from the strainer, open thru hull and check for plenty of water, then replace strainer. Apparently these pods float vertically and this is not unusual in areas in south. Hope this helps someone.
WindPath Sailing, FL