If the transmission manufacturer says lock the prop it is indeed faster as you will not lose the time repairing or replacing the transmission.A locked fixed blade sailboat prop is faster than freewheeling..
This myth is just too nuanced to be included as a myth. As others have noted surfing, planing and heeling boats can exceed the theoretical hull speed. Naval Architects look for ways to exceed the limits.Hate to tell you this but number 5 isn't a myth! its an actual formula that applies to displacement boats! and is the best close predictor for the the maximum speed of a displacment boat. This formula does not apply to boats ( including sailboats) that are capable of planing.
stu could you help me out im still learning what is a combiner and what is an ACR? thanksCombiners can overcharge start batteries.
Overcharging with Combiners or ACRs The MYTH:
http://c34.org/bbs/index.php/topic,7052.0.html
Great topic, thanks for the suggestion.![]()
Lee,stu could you help me out im still learning what is a combiner and what is an ACR? thanks
An important variable is the amount of energy required to get a displacement boat to exceed theoretical hull speed. Once the boat tries to climb the bow wave the amount of energy required to push the boat up hill increases at a very rapid rate. That effectively limits the boat to about the theoretical hull speed. You can see this effect in calm water while motoring. It takes very little throttle to get the boat moving, however as the boat approaches its hull speed it takes relatively more throttle to get a little more speed. On my Sabre 30 with a Volvo MD7A at 2200 RPM I would move at around 5.5 kts. At WOT (~2800) I could get to a little over 6 kts. The first 5 knots were about 400 rpm per knot, the last knot was about double that.With respect to number 5: Yogi Berra once is said to have said, "In theory there is no difference between theory and practice. In practice there is." Theory states that the "hull speed" - maximum speed of a displacement boat - can be closely approximated in knots by 1.39 times the square root of the water line in feet. The displacement hull sits in the trough between the trailing edge of the bow wave and the leading edge of the stern wave created as the hull moves through the water. The bow and stern wave fronts move together at a speed proportional to their separation distance. So in theory there is a limit to how fast a displacement hull moves -- namely the maximum speed of these two wave fronts. In practice however, once a sail boat reaches hull speed additional energy usually produces excessive heal, wind is dumped out of the sails, and the boat stays in the trough. In practice, even a displacement hull can be forced to ride up onto the trailing edge of the bow wave forcing the boat to go faster than the theoretical hull speed without getting up on a plane.
Friend of mine bought an O'Day23 years ago and was trying to pick a name. His non-sailing father-in-law's suggestions: Hole in the Water or Barnacle BuoyWhen I bought my boat (a modest 28' O'day) one of my son's pals said: "Wow! Your dad must be rich". My son replied: "yeah we were until he bought that boat".