Trim tab operation

[Jerold Geisenheimer]

I was charged $300 for the installation which took many hours. Running the wires and locating the components requires considerable thought. One of the components is mounted on the floor of the forward stateroom closet the other is adjacent to the generator fuel tank. Hope this helps. Jerry

 

[baz]

Upon closer inspection of the two Trim tab rocker switches I noticed that the front rounded curved portion does have raised lettering "BOW DOWN". I had never noticed this before -- presumably as the lettering is hard to see. 😉 It would have been more obvious if the raised lettering had a contrasting color to Black.

No matter, yesterday I gave the Trim tabs a good work out and found what Karin & Bruce recommended worked flawlessly. For me, the mystery of operating the Trim tabs has been solved.

I had fixed an inclinometer in front of the helm several years ago and using this in calm waters yesterday the effect of trimming the boat's attitude was quite obvious. Of course, the trick with the inclinometer is to have it set correctly to indicate the boat's port & starboard sides are equal in the horizontal plane. I did have to correct it slightly while at my dock with the boat completely level and with another person in the cockpit to adjust the side-to-side weight distribution.

Thanks to all who have posted on this subject. 🙂

On a slightly different note... My trim tabs are very clean looking and in fact almost shiny to look at. I've noted on other boats, including RTs, in my marina that they have really cruddy looking tabs with huge amounts of growth. It seems that if the tabs are exposed to strong light and sun they get cruddy with growth quite quickly vs. mine that are shielded from strong light and sunlight as I dock stern in so that the stern is very much shaded from the weather elements.

 

[Irish Mist]

Most of the boats in our marina look like that by the end of the summer ( not just the trim tabs ) . I know in their case it is from never leaving the marina. I think lack of use helps give things a chance to take hold. Sounds like that is not an issue with you 🙂

 

[knotflying]

I apply Petit Barnacle Buster to all my metal it is more durable than bottom paint and seems to work well. While on the water for long periods of time I usually get on my snorkel and mask and do a clean-up of the hull bottom and running gear. A hit with a stiff brush and the use of a plastic spackle knife cleans off the growth nicely and those small barnacles just pop off.

 

[baz]

Underwater boat surface area cleaning/scrubbing is forbidden in my marina... although I really see no issue removing crud from the trim tabs myself as I would assume the buildup of crud on them is a non toxic substance.

We have a Diving company inspect our underwater zincs every 3 months and I know they have to obtain a permit to submerge. 🙂

 

[doke01]

Here's how I think of it. The switches are the boat. Imagine a big finger pushing on the boat where you want it to go down. If you want port/forward to go down, push forward part of the port switch. If you want the bow to go down, push down on the forward side of both switches. Starboard aft, push the aft part of the starboard switch.... etc.etc.

I've found I always need to use the trim tabs to obtain proper trim on our R25.

I've also found that in shallow water (3-5 feet) pushing the trim tabs almost, counterintuitively, all of the way down (bow down) helps greatly in speed and efficiency. The prop wash in shallow water greatly impacts forward motion. I think is is because a low pressure area is created under the hull that tends to resist the forward motion of the hull and putting the bow down as much as possible reduces the low pressure area.