Fore-and-aft trim for 16 Cruiser

[marco422]

As I prepared to install a fore-and-aft trim indicator on my boat, I was faced with a little bit of a dilemma. What is the correct trim for a 16 Cruiser? Is it a level cockpit sole? Should the side windows be level? Is the table in front of the helm meant to be level? Is it the waterline on the after half of the vessel?

Thoughts?

 

[oldgrowth]

marco – you are properly trimmed when you get maximum speed at any given rpm or the most comfortable ride in choppy or rough water. I have a lateral trim indicator on my boat, but feel a fore and aft trim indicator is useless.
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Dave

 

[marco422]

I would like to trim my boat at the dock, distributing my load evenly. It's easy to sense and adjust side-to-side, but fore-and-aft seems to be more subtle. I realize that the trim underway will vary according to conditions...

 

[oldgrowth]

If you are just concerned about how it looks at the dock, load it so it looks the best to you.
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Dave

 

[marco422]

If you are just concerned about how it looks at the dock, load it so it looks the best to you.
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Dave

Heh, heh. No, I just want my boat to have a properly balanced load so that it climbs easily onto plane and travels "lightly" on the water. Obviously that is very difficult to judge underway as the boat's attitude changes with motor trim and speed (due to climbing the bow wave). If my boat is poorly trimmed at rest, I can compensate underway with permatrim or trim tabs, but that compensation will lead to increased resistance to forward movement and therefore fuel consumption.

I expect that the C-Dory has an ideal design trim (which I assume would be when the aft painted waterline is parallel to the water) and I wanted to know if anyone had expert or theoretical knowledge otherwise.

 

[colobear]

I'm don't recall seeing or hearing about a theoretical model for trimming as you describe. My sense is that we each develop our own trim arrangements from experimentation. I don't think anyone is trying to diminish your request, just acknowledging the many many variables. As you have alluded, trim changes constantly, sea, fuel, movement, wind, etc. etc. I suppose one could experiment at the dock loading the boat so that the gelcoat color line is level but I'm not sure the line represents a true indication of proper trim. It will be interesting to see what response your request generates and what your own experience offers to the rest of us.

 

[lloyds]

Something I learned on our last long trip with the new permatrim, if the steering has too much resistance then you are probably not trimmed properly. NFB steering might be no feed back but you can still detect resistance. When I felt that and messed with the trim it would ease right up. Steering resistance, engine rpm, and speed are the indicators. My guage is almost useless. It shows trim almost all the way in. On our 16, 4400 rpm trimmed in yields 15 mph +- and changing trim in or out will change that in a minor way to the negative.

 

[ramos]

What I have found on C-squirt is something like this: on calm days if I feel it is more difficult to turn to starboard I have trimmed too far down. If the bow porpoises, I have the motor too far up. I usually trim up until the bow starts to gently bob and drop it back down just until it stops. This almost always results in max speed at that particular RPM. At docking speeds I usually trim a bit bow-low as the stern will pivot around the bow just ahead of the helm. When it gets rough, I slow down and trim for comfort and forget about economy. Forgot to mention, we are using a permatrim.

 

[DaveS]

and forget about economy.

Now your talking. With a 16' Cruiser that is already a "fuel miser", I wouldn't be overly concerned about it. The majority of folks on the water spend more money on fuel idling their engine/engines before departing the dock than you can in an 8 hour day of cruising at 3/4 RPM. I certainly didn't lose any sleep over the amount of fuel I put in my former 16' Cruiser. As for balancing the vessel, I used to move items around (and still do with our current 22') the vessel while underway as to what seemed to work best for the "conditions" I was currently in. When the sea conditions would change, I would make the appropriate adjustments as to the locations of heavier items.

(P.S. On re-reading "marcos" initial post, I don't know that there is a "textbook" measure of the proper way for "trimming" and would suggest, that only what works best for you and your vessel would be "proper"). There certainly was a time or two when our 16' was so LOADED down with equipment and "necessities" that anyone observing it would have chastised me for having such a load, but we at least made it to our camping spot on Lake Roosevelt, unloaded the bulk of weight to our "camp" on shore and proceeded to enjoy a wonderful week in a much lighter vessel. (With all the stuff we had with us on those trips, there was no such thing as "trimming".... :roll: ).