Dominique C.

05:45 departure in calm conditions.approx 45 mins before sunrise. glassy waters, 15C, nil wind, cloudy skies. rising tide near high tide, 1 KT current to the north. engine water temp alarm approx 1NM North of Jekyll Island bridge near marker 19. shut engine down, dropped anchor safely off ICW main route to minimize obstructing traffic on a narrow channel. anchor marker buoy proved extremely useful to indicate position of anchor to other vessels, so they could safely avoid anchor rode. having noticed water no longer ejecting from exhaust, initially suspected seawater thru hull pickup was obstructed. raised scuba pennant, donned snorkel gear and attempted to dive in 12C waters, no wetsuit, zero visibility in water, 1 KT current. fortunately, alligators in the area are still hibernating for another 2 weeks or so! having no visibility underwater and a noticeable current, took two attempts to find thru hull. second attempt was successful, thru hull was clear. unfortunately, suffered several minor cuts on both hands due to feeling around with some barnacles on the hull. in hindsight, it would have been preferable to put a spare bilge pump hose or a shop vac in/on the seawater intake strainer inside the boat to determine flow and possibly clear any potential obstruction. this would have avoided the need to dive in cold water, suffer from minor lacerations to both hands resulting in bleeding, and mild hypothermia due to diving in cold water. not to mention saving time and avoiding encounters with alligators. having determined seawater pickup was clear, attention was turned downstream to the seawater pump impeller. following inspection, pump impeller had 5 of 9 vanes broken off, with remaining vanes cracked and damaged. impeller was removed from pump and broken pieces carefully accounted for. fortunately, all pieces were accounted for, which meant no debris entered the heat exchanger. with a now unusable engine on narrow channel waters, sea tow membership was put to good use. called dispatch, provided position information and indicated that tide was low at that point. sounder showed 2.2ft (later nil ft) depth under keel. eventually, keel rested firmly on soft, muddy bottom. tide would begin to rise at approx 1300, with high tide predicted for 1700. we determined with sea tow captain that a 1430 rendez vous would be the right time to assess and attempt a tow. recovery boat arrived on time, anchor raised with some difficulty due to having been bedded in thick clay. thankfully this boat is equipped with an anchor windlass. tow line attached to both bow cleats. boat was still sitting on clay bottom but not heeled and so was smoothly and gently tugged into deeper channel waters. rest of the tow was smooth and uneventful. called Jekyll harbor Marina to advise of our arrival and to reserve a transient slip, Marina staff were very accommodating and helpful. docking was smooth and uneventful. then came the challenge of searching for a replacement impeller. several calls to several businesses and mechanics later, was able to source parts at lambs yacht center in Jacksonville, FL approx 1:30 minutes south of Jekyll harbor. 24 hours later, two impeller kits had been purchased (one spare) along with new pump cover that was showing significant scoring. pump was cleaned. impeller, o-ring and pump cover were covered in silicone grease then installed. four pump cover bolts were dabbed with anti seize and tightened snug. engine was started, ran for approx 5 minutes, healthy and continuous flow of water was observed being ejected from exhaust. repair declared successful and planning for departure the following morning was done. hardest earned couple of nautical miles so far. lesson learned: this boat has been new to me for a few months now, and despite certified mechanical inspection, the seawater pump impeller was overlooked. it is recommended by the engine manufacturer for this boat to change the impeller every 1000 hours. other sailors simply set a rule to replace the impeller every year. in any case, do not neglect maintenance, care and attention of this critical part.