Slapping

[DaveInRI]

ttking885, Yes that sounds nice and now I remember that part of the previous conversation but still it doesn't address how much slapping is okay. I have twin 40's and I just lower them all the way and it helps greatly.
I see in videos of C-Dory's crashing through inlets and over the steep waves. I would think that they are really pounding violently.

Trim tabs will only be noticeable at higher speeds, but a permatrim or wedges are available/ effective at all speeds. Check that your boat is properly sitting on her lines also, both at rest and underway, and see if there’s any weight you are already carrying which could be shifted around inside the boat. A full load of fuel isnt always helpful in that regard, also (lot of weight aft of you don’t need the range). A full load of passengers or lots of provisions in the cabin helps a lot, though. Lastly, as someone who is always passed and glared at by v-hulls of all sizes clearly displeased at my slower speed coming out of our crowded channel into the northern reaches of our bay, them unfazed at the 2ft/4sec daily dose of wind chop while I’m “working” to get through uneventfully, my mantra I borrowed from somewhere is “boats don’t pound, captains pound.” (Oh, and it’s different but smoother to ride rollers than chop; rollers don’t invite pounding if you’re not going airborne. If you’re in choppy waters, find your own wave height / period formula. Eg, the old 1:4 might not work if the height is 2’ for you / your wife, but taller:further or shorter:closer might. The worst thing to have on a boat is a schedule, so it’s better to be in wishing you were out than out wishing you were in.

 

[Donald Tyson]

“boats don’t pound, captains pound.”Ha Ha, Also Wives pound, At least mine pounded me for going too fast, However, I have trim tabs and Wedges on their way and will experiment with them soon.
Thanks to all the comments here I feel that my expectations are somewhat re-aligned with reality (what to expect). I realize it will still smack hard when exiting the barnegat inlet but slapping should abate a little in normal Barnegat and Chesapeake bay conditions. Thanks everyone. I'll post results later in year.

 

[ssobol]

Trim tabs will only be noticeable at higher speeds, but a permatrim or wedges are available/ effective at all speeds. ...

Wedges just shift the engine trim neutral position (positive or negative). This can give more range to pull the engine in closer to the hull (negative engine trim angle). This may help on relatively vertical transoms. Depending on the boat, engine, and mount you may be able to trim the engine into a collision with the hull.
Trim tabs and Permatrim require the boat be moving to generate any bow down force. Permatrim may be more effective at a lower speed due to it's size and position further aft. Depending on how it is mounted a Permatrim can also be trimmed to lift the bow up. Tabs can only push the bow down.
Disadvantage to wedges is that they are fixed and effectively permanent (for any given voyage). Trim tabs can be adjusted to based on water condition, boat speed, and boat loading. A big advantage to trim tabs is that they can be adjusted for lateral loading as well as longitudinal loading.

 

[thataway]

A few caveats: The Permitrim is the best foil on the C Dory--I have had boats which came with other foils, so I had a comparison in the same boat, same setup otherwise.

There is a danger in trimming the bow down with weights--that is if you are going down wave, you want the bow trimmed up..I don't know if the wedge gives makes it more difficult to bring the bow to a good running position, since I have never used one.

If you put the wedge in, I would pull the motor, route out the mounting holes, seal the core with neat epoxy and fill the sides of the bolt mounting holes with thickened epoxy to avoid any water intrusion into the transom core.

Trim tabs offer side to side trim--there even automatic ones. That keeps the boat level as crew moves around.

In all cases it is essential to avoid bow down and bow steering, where you can loose control of the boat if the bow is too far down in moderate to heavy seas.

Many will, "I always avoid heavy seas or running in xxx*** sea conditions"....The reality is, sometimes storms come up and weather forecasts may not be precise. Sometimes distant storms can produce heavy rollers, even steep waves, if against currents.