Clean Your Bottom or Drag Your A**
Sutton says these two images show how quickly an untreated hull will foul in salt or brackish water.
One thing I will mention is I did not have an appreciation for the importance of having the hull bottom cleaned. This was evidenced by our experience when we tried, initially, to leave Ortega Landing. As soon as we cleared the Ortega River Bridge and tried to run our normal cruising speed/RPM I sensed something was wrong. I knew the bottom had some growth, but it did not look that bad from the finger dock, I kept thinking, given we had the bottom cleaned sanded and painted in September that all we would have to do is start cruising and the growth would not be an issue.
Well, as we approached Jacksonville both engines were running hotter than normal and we had steam accompanying the exhaust water stream and the engines would not run faster that 2200 rpm. We knew something was wrong, but we thought we might just continue on a a reduced speed. But as luck would have it, when we hit downtown Jacksonville the train bridge was down for maintence and would not open till 2:00pm. Given that there was no way we could make our first leg to Fernandina Harbor Marina before dark, we turned around and went back to the dock at Ortega. Fortunately we did not have to move the boat from the dock till June 6th so we still had a slip.
The next morning I changed the impellers, to be sure they were not the issue causing the over heating, even though that looked fine. The next day we attempted to leave again. Unfortunately the impellers made no difference, so we again returned to the dock, but this time docked bow in. Interestingly the growth was more obvious with the opposite side toward the finger dock. I jumped on the phone and called Blissful Bottoms and Bottoms-up dive services and fortunately Wade from Bottoms-up call me quickly and was in the water cleaning the hull at 8:00am the next day (never heard from Blissful Bottoms).
Wade finished in about an hour (charged me $2.50 per foot vs the $3.00 he had quoted on the phone thinking the bottom was really bad, he normally charges $2.00). He said the bottom had a good layer of slime but not terrible, but the props were in need of being cleaned, zincs were still quite good. The prop speed was still there but it was 3 years old and no longer effective and it was pasted its prime. So with Wade gone, we fired up the engines at 9:30am and pushed off once again. Instantly I could tell things were back to normal, what a difference and no overheating and rpms were back to normal too!
The experience gave us as “freshwater boaters” a new appreciation for the importance of cleaning the bottom in salt water on a regular basis. So, we have talked with the diver here in Brunswick ($4.00 per foot) and he recommended we do it every 6 weeks while we are not cruising the boat.
Michael Sutton owns the N47 Southern Grace, which he keeps at Palm Coast, Florida.