Barnacles and Friction

[Racer57]

I have a 2007 Four Winns Horizon 180 with a 135 HP Mercruiser. Garage kept so no bottom paint.Top speed has been a very consistent 42 - 44 MPH.

A friend let me keep the boat in their wet slip in the Intracoastal waterway (salt water) for about 17 days. About 78 degree water with only tidal flow.

When I tried the top speed, could only do about 25 MPH.

When I pulled the boat out last night, as expected, there was a significant amount of barnacles that I had to pressure wash off.

Can just 17 days of barnacle growth provide that much friction to wallop the performance so much?

 

[dwco5051]

Simple answer, YES

 

[Chris1956]

Some hulls can absorb water as well. Since your boat is pretty new, I would hope the OEM guarded against that.

 

[SeaDooSam]

Yes it definitely could. The barnacles drastically increase the surface area which contacts the water which in turn leads to more drag and slower top speed

 

[shrew]

Yes Barnacles cause friction. Any marine growth will affect performance. Can 17 days of growth cause this? Not in many cases, but apparently in your case it does. You're going to need to get the disks off of there too. When you knock barnacles off, they often leave a flat disk behind which will also need to be removed. I would try a hard plastic scraper. Good Luck.

 

[Bondo]

Ayuh,..... Even the green slime formed on the hull in freshwater, 'n sunlight will seriously slow yer boat, 'n increase yer fuel bill,....

We don't have Barnacles, but the Zebra Mussels do the same darn thing,.....

 

[shrew]

Incidentally Mary Kate On & Off Hull Cleaner is GREAT at removing marine growth, including barnacles.