I am led to believe that as a displacement hull
moves faster and faster its bow wave lengthens until is is the same as the waterline length. If the bow wave created were LONGER than the WL the boat would be trying to sail up the wave as the stern would then be in the trough of the bow wave. Since this appears to "impossible" (not sure why) a hulls speed is constrained by its LWL.
Because a sailboat heels, its hull
shape at LWL can change AND lengthen meaning that it hull speed
would be greater than the static LWL.
I have observed that my hull will begin to "squat" the stern in the water
when "over powered". At anchor
the CL of the stern is about 4 - 6" above the water
(guess) but at hull speed
it appears to be 3+ inches below the water. This is obvious when motoring.
I have made some other observations and would like others to comment.
At speeds LOWER than hull speed, perhaps 85-90% of hull speed the stern ALSO dips a few inches which seems to indicate that the bow wave exceeds the LWL before reaching hull speed. Is this possible?
Which LWL is the one you use to compute hull speed, the windward or the leeward one? I think the windward is shorter. Would this be true and does it matter? Why would the bow wave be symmetrical if the hull shape when heeled is assymetrical...
How much bouyancy is there at the stern of the boat... the very back? Does the buoyancy at the hull vary based on it's area contact with the water?
Can anyone dirert me to a resource for non naval architects which explains this?