loss in Speed

[hammlfam]

Hello<br /><br />I docked my boat in the water this year for the first time. It is a 94 Stratos F/S with a 120 Johnson. She normally would run about 44/45 with my wife and son in her. Well , the past couple of weeks, I could only get about 41/42. The Rpm's held the same as before around 5400 and the motor sounded just fine. I pulled the boat out of the water 2 day's ago to clean it up. There was a tremendous amout of buildup on the boat and the motor and prop. I have since cleaned it up to new condition. Would this have affected my speed at all?<br />Thanks

 

[Jdeagro]

Re: loss in Speed

Keep it as clean as possible.

 

[hammlfam]

Re: loss in Speed

I will, but could this have been my problem?

 

[MajBach]

Re: loss in Speed

Definately! I have observed losses exceeding 10% from a dirty hull.

 

[roscoe]

Re: loss in Speed

Test results from boatfix.com <br />This test was done in saltwater, but you get the idea.<br /><br />To show the dramatic effect cleanliness plays, a boat was left anchored in salt water for 40 days. The running tests were made with a 35 HP engine which was removed from the boat after each test. A three-man load was used.<br /><br />Speed:<br /><br />At beginning of test . . . 25.0 mph (40 km/h) <br />After 10 days in water. . 21.5 mph (35 km/h) <br />After 20 days in water. . 18.5 mph (30 km/h) <br />After 40 days in water. . 13.0 mph (21 km/h)

 

[hammlfam]

Re: loss in Speed

WOW, thank you Roscoe.