I anxiously dropped the Cabin Skiff off the trailer for the first run since the bottom repair. I had decided to leave the trim tabs off as I want it to be a true test of the hull without any lifting assistance. The boat was loaded with 11 gallons of fuel and 2 passengers (about 340 lb total).
With the outboard trimmed all the way down I dropped the throttle. I immediately noticed that the bow did not rise and much as before and it seemed to plane a little quicker. I brought it up to cruise speed at about 5200 rpm and all was well - no bow bounce. In fact I noticed that the speed looked good although the steering was a little heavy. It really needed some up trim to lift the bow. I added considerably more trim than ever before to get it where it needed to be. What a great feeling. I purposely trimmed up too far to try to get it to bounce but it blew the prop out first. The water was very smooth at the time. I tried it again later with a little rougher water and it started bouncing but I could stop it at any time but dropping the trim down a little. This is how it is the way it is suppose to be!
Next I decided to slow it down and see what would happened. Before the repair the lowest speed I could hold and still be on plane was 19 mph. Now at 16 mph it is still hanging in there.
So how about top end? Well there is good and a little bad news. The good news is I have picked up a solid 2 miles per hour ( maybe a slight bit more) at wide open throttle. The top speed is now 32 mph+. The bad news is I have also picked up about 400 rpm. This isn't really bad as obviously it is performing much better than before. The down side is I was already a little under pitched and could over rev the engine by about 200 rpm before the fix. Now it will easily turn 600 rpm more than the maximum suggested by Honda. This is enough that I will need to have both of my props re-pitched. This is not a complaint though - I am thrilled with the result.
This goes to show that even though the trim tabs and /or planing plate can lift the transom, the drag created by the defective hull shape was still there and diminishing performance. Plus adding these devices to correct the problem create additional drag and use horsepower to overcome the original problem. It is a "lose - lose" situation. This underscores the importance of keeping the bottom flat, particularly in the aft planing sections of the hull.
Even though not needed for normal operation I have decided to re-install the trim tabs. I already have them and they should not add any drag if not deployed. At times today the water got a little choppy (about 12 mph wind) and even with it trimmed all the way down the ride was a little rough. In wind above this level I have found the trim tabs very useful. By slowing down to about 18 or 19 mph and using the tabs to force the bow down it will really smoothes out the ride. Fuel consumption goes up but still I am able to maintain a decent cruise speed without having the fillings in my teeth jarred out. Without the tabs I would just have to drop it off plane and accept a much slower speed.
I am really looking forward to my first full season with the Cabin
Skiff. Now that I have performing as per design I am ready to log
some serious miles. Since its maiden voyage the end of July 00,
I have about 1500 miles and 100 hours logged. I am tentatively planning
a nice trip for the first part of May. I plan to drop in at Kentucky
Lake Dam and follow the Tennessee River to Chattanooga, TN and then back.
This should be a round trip of about 950 to1000 miles. I can't wait!