posted 11-15-2004 11:31 PM ET (US)            

I too have a 25' Revenge W/A, with a single 250hp Yamaha.
The tabs were installed by the previous owner, and I think that they are placed too close to the center of the boat.
Therefore, there is less control for stabilizing from side to side, but their control for trimming fore and aft are awesome.
In heavy, steep, chop (read: everyday),I can bring that sharp angled bow down very nicely to slice into it for a much improved ride. Using the trim on the motor plus the tabs gives excellent contol in various waters.

My rule of thumb:
In to a head sea:
If your have nasty chop, lower the tabs to drop that bow, to slice into them which will smooth the ride.(sometimes just a wee bit wet)
If the water is relatively smooth, bring your tabs up and motor trim up for better speed and economy.(generally dryer too)
If your need to plane at a slower speed, dropping those tabs will really help.

posted 11-16-2004 08:01 AM ET (US)            

Sheila, You will find that you will need to adjust the tabs in various conditions as Macfam says. In addition to that you'll probably find that your Whaler will lean or list into the wind when you are on a tack that is not into the wind. The windier the conditions, the more it will list. The reason for this is that to maintain your course, you actually have to steer into the wind and when you do that the boat banks in the direction of the steering input just as it does when making any turn. When the boat leans or lists into the wind, the hard chine tends to bang on the waves making the ride uncomfortable at times. To reduce this, slowly drop the windward tab down until the listing has been removed. The windward trim tab will tend to act as a shock absorber. Because there is usually a little bit of a delay between the tab actuation and the boat reaching a new equilibrium, when I use the tabs, I will typically push the up or down button for about a count of "one" or "two" and then release and let the boat adjust. If it needs further trimming, do it again.

posted 11-16-2004 08:51 AM ET (US)            

I've been correcting for list "the old fashion way", yelling

HEY YOU!!! GET OVER TO THE OTHER SIDE OF THE BOAT, AND TAKE THE COOLER WITH YOU!!!

posted 11-16-2004 09:05 AM ET (US)            

That is a heck of a lot cheaper solution than my trim tabs, (but I still like them).

Shiela-

If you give serious consideration to trim tabs, check out Lenco electric tabs along with anything else you look at. Less hardware and easier to install, crisper response. There is a fair number of threads on the pros and cons of electric vs. hydraulic tabs in the archives if you search.

posted 11-16-2004 12:05 PM ET (US)            

Kingfish, the trim tabs are already on the boat. I'm just trying to learn how to use them properly.

posted 11-16-2004 10:27 PM ET (US)            

The Bennett tabs you have will work well. If you experience problems with their function in the years to come, it will usually be with either the dash switch, or the harness at the pump unit.

posted 11-16-2004 11:55 PM ET (US)            

It is rather hard to get the bow of a boat with a Whaler Drive to ride too high. If you trim the engine out to try to push the bow up, you end up trying to push the Whaler Drive down into the water. It won't go very far. The bow won't come up very high. The Whaler Drive is acting like a big trim tab. Most of the Whaler Drive boats I have seen on plane tend to ride with the bow rather low. Most of the hull is in the water. You cannot get too much bow lift by trimming because of the effect of the Whaler Drive. Whaler Drive boats tend to "slide" up on plane--very little bow rise. Again, I think it is the Whaler Drive acting like a big trim tab.

posted 11-17-2004 08:29 AM ET (US)            

The boats with the brackets have some advantages.
Usually the transom is solid or closed, which can help eliminate engine noise, smoke etc.. In addition, the angle of thrust is affected, and can improve some performace aspects, and it usually allows for more room in the boat.
It's acts like lengthening the boat.

Back in the 80's, Boston Whaler produced their own version of these brackets, known as Whaler-Drive. It's a permanently fixed appendage, behind the transom to which the engine(s) are mounted. The vast majority of these installations are twin engines.
The Whaler-Drive appendage is also foam-filled like the hull, and added to the flotation. It acts like a giant trim tab as jimh has described.

Take a look at the Cetacea section of this website, page 63.
You'll see Whaler-Drive, standard cut-out transoms on the 27', and even another bracket or two.

I'll get some pictures of my boat to ya soon.

posted 11-17-2004 08:55 AM ET (US)            

Jim, I still don't understand why one would call a Whaler Drive "one big trim tab". Rather, I view the Whaler Drive as simply an extension of the hull taken from the original transom which relocates the "transom" and the motor(s) hanging thereon 2 or 3 feet further back depending on the model.

I think your trimming and attitude observations have more to do with the bouyancy of the Whaler Drive and the location of the center of gravity than hydrodynamic "trim tab" effects of the Whaler Drive. The Whaler Drive versions of the 22 and 25 were meant to have 800 to 900 lbs of outboards hanging on the relocated transom. When you put a single engine on a WD, you only have about half the weight that was intended to be there. In such case, the center of gravity of the boat is going to be further forward making it more difficult to trim the bow up. Every Revenge 22 WD that I've seen with a single outboard appears to rides bow low because I believe there isn't enough weight on the Whaler Drive to counter its bouyancy.

posted 11-17-2004 09:43 AM ET (US)            

I understand with twin motors, both on brackets and on a notched transom, the attitude or trim of the motors can be adjusted independently too, enough to provide some lateral trim for the boat. My contention is though that to do so without tabs, or to adjust the boats fore and aft attitude with just the motor(s), while sometimes preferable or necessary, adversely affects the performance and efficiency of the motor(s), much more so than by maintaining similar and neutral trim with the motor(s) and trimming with tabs.

Even with a bracket or a "mega" bracket like a Whaler Drive, tabs (if there is room for installation) add options for performance that are not there in the absence of tabs.

posted 11-17-2004 11:31 AM ET (US)         

I guess there are two ways of looking at it. Peter prefers to simply consider it an extension of the hull, say, turning a 22 Outrage/Revenge into a 24' boat. So that would mean the 22 now planes off like a conventional 25 would, and runs at a similar attitude. My experience is that the 22 WD planes off with less "dig" than the 25 notched transom does, but I still think this argument is reasonable. The Whaler Drive is almost an extension of the hull, but not quite, as it is slightly higher than the hull bottom itself.

posted 11-17-2004 03:21 PM ET (US)            

And everyone, this discussion will help us get the "feel" for using the trim tabs.

posted 11-18-2004 10:33 AM ET (US)            

My name is Christian and I work for Bennett Marine. The forum members have already given you some sound advice for using your trim tabs, but it may also be helpful for you to download a new Bennett owner's manual.

Download here: http://www.bennetttrimtabs.com/ownman.pdf

See pages 3 and 4 to a quick lesson on how to best utilize your trim tabs.

posted 11-18-2004 04:45 PM ET (US)            

It is more efficient to adjust the boat's attitude using trim tabs than it is to trim the outboards. Optimum efficiency on most all outboard powered boats is acheived when the propeller thrust is aimed straight back--parallel to the water surface. If the prop is aimed up or down you are losing some forward thrust. With trim tabs, you can control the attitude (raise/lower the bow) by using the trim tabs, while keeping your props trimmmed parallel to the water surface.

The follwing is copied and pasted from our website. Hopefully this isn't misconstrued as an adverstisement for trim tabs, but I thought it would be help answer your question:

TRIM TABS AND POWER TRIM

Power trim can be used to adjust the boat's attitude, but it is highly inefficient. A propeller is designed to force the boat forward. When trimming the boat with the prop, the prop must not only push the boat forward but raise the stern as well. In this situation, prop slippage is greatly increased thereby wasting RPM's. Power trim cannot correct listing, and is ineffective at slower speeds. Trim tabs, in combination with power trim, enable both the hull and prop to be trimmed independently. The trim tabs trim the hull, while the power trim adjusts the prop. The result is optimum performance and efficiency not attainable by the use of power trim alone.

To achieve maximum performance, first adjust the trim tabs to achieve the desired running attitude. Next, use the power trim to position the propeller thrust parallel to the water flow. If necessary, re-adjust the trim tabs to fine tune the attitude. By observing the boat’s speed and engine RPM's the best combination of trim tabs and power trim will be apparent. Trim tab angle indicators and a power trim angle indicator are particularly useful in duplicating effective settings.

Christian
Bennett Marine

posted 11-18-2004 05:09 PM ET (US)            

I would agree with LHG that the tabs are not necessary on a 25. I even had a 22 WT that didn't need them. However if they are there they are there! I don't know what boat you have. Is it a "cut out" transome or a WD. With twins and CR rotating props the "torque" factor is eliminated. Some times a single was fitted with a "shingle" to over come torque lean.Z Both of the Revenge boats I had were fitted with twins. The 22 did not have counter rotating props. However you did have to play with the T&T (tilt and trim) a little to make it work. It wasn't a problem. Use them (its just another system to mess with) when they go bad ditch them and repair the hull. "Swolmaster" (I think that is how its spelled) was on my 25 WT a year ago last summer in Lake Huron and couldn't believe I didn't need the "Tabs". He is from FLA and sees a lot of big water!.

You asked in another post about spare equipment. Other than the usual USCG requirements I would go with Bacdua and keep it simple. I boat on lake "Huron" I keep water and food "canned" for 2 days (why 2 days? a child or "grand child" doesn't understand how bad a sea can get!) by the way only two meals a day (in a pinch) and sufficent clothes (to keep warm)(nobody wants to be cold and hungry!) housed in a 20 quart cooler inside the cabin. (only the clothes are in the under step entrance to the cabin, in the 20 quart). It is amazing that the "Igloo" will keep things dry as well as "cold"!don't understamate it. A tool kit "yea" simple your not going to rebuild and engine on the water. As for the spare "Prop" leave it at home. You are not going to replace it in 6' waves even if you are willing to go for the swim. I have proved without a shadow of a doubt that a spare SS prop is a waste of time and weight as well as space. I did some serious "dredging" east of "Turnbuill" Island in the "North Channel". I basicially "lunched" two gear cases and "skegs" and bent the port engine drive shaft out .38 TIR (total indicated run out). The engines brought me home, with some vibration about 50 miles (statute)!

Remember, as you boat, sometimes it is better to "hide " in a cove behind a large rock than make a "run" for home! The surge may be bad but he waves are worse! Also your boat will take more "beating" (physically) than you can.

As a final thought, I don't know the geographincal arrangement of the area you are in. If it is rocky, "not gravel", you might want to invest in some "nuts" and "carribiners" (the stuff rock climbers use) makes tying off to rock formations very easy.

As for renaming, name it what ever you want. It is superstition!. Besides the "Coast's" like a name on a hull to match with the registration number on the hull if they are looking for you.

I wish you the "BEST"
have funn!

posted 11-18-2004 08:56 PM ET (US)            

Christian, thank you for explaining about power trim vs. the tabs.

WLS, thanks for your thoughts. The boat is a 25' Revenge Walkaround with a notched transom and a single outboard with a kicker starboard. Does that help?

posted 11-18-2004 10:00 PM ET (US)            

I have three "Igloos" I carry. Two mounted in the cockpit on the gunnels midshps- (60 quart). The are secured by shock coards. One is a line locker on the stbd side the other is the "galley" and storage locker. The "galley" houses a work table that is mounted in one of the fishing rod holders and will mount a 2 burner propane stove. Packed correctly it will store the stove, table (I think it was Magma) 2 cans of fuel a mop and brush set as well as a set of SS pots and pans that nest together along with 2 days of provisions in cans and flat wear for 4. I also have water pruification tablets (yuck) in case I run out of bottled water. The third is mounted in the cabin under the step down to the cabin.

The "Igloo" will sustain a teriffic amount of water and keep your "stuff" as George Karlin says dry (I have flooded the Cabin!). They also really float well. You can use them as a throw-able to a boater in distress. A true mulit tasker. I keep my beach towels swim suits and sun protection gear and rain suits in the locker in the cabin. I use the lockers under the bunks for the running top and "linnens" When I go out very far I always carry a "day" bag. IMHOP the Igloo is the most underated property on a whaler. It makes great storage, "works as a cooler" as asked, keeps things dry and safe and is a "life saver" if called uppon. And with the "cushion" you get another seat!

Again, have "Fun" with your new boat!

Later
WLS

posted 11-18-2004 10:45 PM ET (US)            

As a follow up. Do not put anything heavy in the bow line locker. It will break the rather "weak" bulkhead and seal between it and the cabin. Hence a "leak". The drains for the locker are rather small and if slightly blocked will not function! The drains come out of the hull just in the Upper "smirk" and are I think PVC. They are rather small.

As a side, I was towing thru "Detroit" (other wise known as "mug" city) about 10 years ago. I hit a "pot hole" so large on the "Lodge" that the cover on the forward line locker came open to full extent. I couldn't believe it. I had to tow for about 20 miles before I could stop and correct the situation.

Best

posted 11-19-2004 09:24 AM ET (US)            

By all means keep the trim tabs. IMO they are the single biggest performance improvement you can make to almost any boat. There is a learning curve involved in using them properly and once mastered, you will never want to go back to using only engine trim to adjust boat attitude.

Christian summed it up very nicely...It is more efficient to adjust the boat's attitude using trim tabs than it is to trim the outboards. Optimum efficiency on most all outboard powered boats is acheived when the propeller thrust is aimed straight back--parallel to the water surface. If the prop is aimed up or down you are losing some forward thrust. With trim tabs, you can control the attitude (raise/lower the bow) by using the trim tabs, while keeping your props trimmmed parallel to the water surface.

On my 21' Walkaround, I normally adjust the engine trim so the prop thrust is parallel to the hull bottom and leave it there. I then adjust the boat's attitude with the trim tabs.

Larry,

WOW! I thought my eyes were playing tricks on me...

quote:

---

A bracketed situation like "Whale Lure", WITH trims tabs (which the boat does not have), would be the optimum situation...

---

Steve

posted 11-24-2004 12:13 AM ET (US)            

Perhaps you could email him with your questions and see what he has to say?

posted 11-24-2004 10:48 AM ET (US)            

As Sal states the milage is so darn lousy anyway, I'll trade of 2.5 mpg to 2.2 mpg for comfort.
No matter how you slice it, your paying about a buck to a buck and a half for each mile(don't tell your wife that)......might as well be comfortable!!

I had a 1982 V-20 Revenge. If I knew then what difference the tabs make, I would have put them on. I wish I had.
However, (and we're talking about wives here) I EASILY convinced my wife we needed the 25', "because I couldn't take the pounding anymore".

End's up, the 25' Walk-thru is the "perfect" boat for our needs. Love then tabs!!!

posted 11-24-2004 10:29 PM ET (US)            

Trim Tabs can only make the bow go down, never up, unless it already wants to go up and the tab is holding it down.

Tabs are useful for correcting a list in the hull that often results if running in a cross wind.