Bennett Trim Tabs

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Bennett Marine

Giving Competitors a Serious

"Attitude Adjustment!"


Bennett Review by:

Allen Applegarth

Industry Insider

Bennett Marine is located in Deerfield Beach, Florida and is the world's largest manufacturer of trim tabs. They have been on the forefront of innovation since 1960, and the inventor of the modern trim tab system is none other than Charles Bennett.

Trim Tab Overview

Trim tabs are to a boat, as to what rubber tires are to a car--simply necessary! In general, trim tabs allow the hull's shape to be dynamically tuned for optimum performance in all conditions. They help get the hull on plane more quickly, keep the boat on plane at slower speeds and provide a higher level of seaworthiness. Additional "Bennettifits" include a softer and drier ride in rough water, increased speed and improved fuel economy.  This is achieved by placing a pair of metal tabs on the transom with some sort of actuator to raise and lower the tabs.  The tabs are then controlled via user control at the helm.

Do I Need Tabs?

Do you want to stay dry? Be able to plane at very low speeds? See in front of you at take off or plane quickly from shallow water? Save fuel?  Gain speed? Ride level with no list or high bow? Cut through stiff chop as if didn't exist? All boats need tabs!

I Plane off Fine using my Motor Tilt /Trim!

Although power trim can be used to adjust the boat's attitude under certain conditions, it's a very inefficient method. The propeller is designed to push the boat forward. When trimming the boat with the prop, not only must it push the boat forward, but raise the stern as well. In this situation, prop slippage is greatly increased and  undo stress is placed on pivotal points, thereby compromising efficient engine operation and shorting the longevity of the motor.  Power trim also cannot compensate for listing (leaning over to one side), nor will it allow you to plane at lower than normal speeds.

About Hydrofoils

While they do provide a little more lift than just the ventilation or cavitation plates, you are still forced to use your tilt/trim which actually adds more stress to your motor.  They also can make your ride worse by digging when your boat starts to list.  This in turn puts  unusual pressure on pivotal points.  I don't know about you, but I like my lower unit and want it to stay healthy for many years, as they aren't cheap! Let the trim tabs do the work and your motor push you!

Electric or Hydraulic?

Many boaters opt for hydraulic based on the wide spread word on the street that they are much smoother, use less power, are always lubricated, make less noise than ball and screw electric, and corrode less.  I can't make that judgment call just yet, as I haven't had a chance to try out anything other than hydraulic.  I will be comparing the two in the near future so check back here at FIA and look for the product review and comparison article.

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Author: Allen Applegarth

Whether you want to look at attitude as the position of your boat in the water, or the beliefs, values and innovations behind the world's largest manufacturer of trim tabs, you're sure to find the best of both at Bennett Marine.  Not only are their products outstanding, but equally are the staff that make up Bennett.  At first glance you'll quickly notice prompt and courteous service, a very knowledgeable staff and unrivaled customer relations. Upon product inspection you'll see why many boats are equipped with Bennett's system.  What's left?  Nothing!  

Over the years boat hull designers have stepped up to the plate and started creating designs that handle better, are stronger, faster, make less noise, and so on. On the other side, trim tab manufacturers have had the challenge of keeping up with and even surpassing hull designers to complement an already good design, and that's exactly what Bennett has done with their latest line of trim tabs and accessories.

atc.jpgBennett has substantially raised the technology bar with its latest and greatest Auto Tab Control, or ATC; a system that is unmistakably engineered by Bennett Marine. Designed to incorporate seamlessly with an existing Bennett system, the ATC is the trim tab system for "Dummies."  Well, not exactly, but the intelligent CPU takes all the guesswork out of tab control and leaves the captain virtually hands free to navigate.

ATC Control Unit.jpgThe ATC Control Unit acts as both a sophisticated processor and attitude sensor. Once programmed, which is achieved by simply running the boat in the trim position that you feel is optimum and then pressing a button to set the memory, the ATC then "remembers" that setting and automatically keeps the boat running at the desired attitude by self adjusting each tab. The Control Unit calculates and analyzes attitude readings more than a thousand times per second. It averages the readings and is programmed not to react to every wave This allows the systems to react to more long-term movements, such as those caused by load shifting or an already unbalanced load.

The ATC can be easily switched to manual control via its own operating keypad (shown in fig 1), which allows you to turn it on or off at the push of a button, or simply by pushing one of the manual tab switches. This ensures that you have instant tab response in case you need it in a hurry.

While an automated system such as the ATC is a breakthrough in the industry, it certainly wouldn't be complete without the end product, a set of high quality well engineered tabs to take advantage of this technology.

m120tab.jpgThe M120 series batwing tabs fit the bill perfectly. Bennett really did the traditional flat tab system justice with the downward folding wings and a unique center bevel that amazingly grips the water with authority. The wings provide superb stability and channel the water in a manner that provides greater lift.  Not only do the M120's provide increased lift and stability, they also take up much less space.

 Install & Sea Trial

SYSTEM: M120 Batwing tabs / Auto Tab Control / Electronic indicator Control / Auto Tab Retractor

NOTE:  Due to the complexity of this system, and the need for long term durability testing,  this review will be in 2 parts. Part 1 will cover the install,  functions and test ride of the system, and part 2 will cover the durability of the components.   

I don't know about you, but me, I'm a gadget guy. As so,  it takes a lot to get me excited.  When I found out that Bennett came to market with this system I had to have it.  Did I also mention that I love automation!  Needless to say, this system was right up my wake and calling my name!.

Upon deciding to go with Bennett, which was just a matter of me googling their phone number, I spoke to them several times on the phone, not trying to figure out what components that I wanted, as I already decided on a complete system, but rather trying to figure out what size tabs I wanted. My 20 foot Hewes originally came with 12x12 flat tabs, so obviously I wanted no less than 12x12 tabs because I wasn't getting the kind of lift that I wanted, and ignoring their suggestions at first, I insisted on stepping up to bigger tabs. I thought for sure that bigger tabs meant bigger lift and better control.  Finally, I went with the tabs that they recommended, which were actually several inches smaller and made me a bit skeptical.

The day it arrived I saw the box as I pulled into my drive.  Anxious to see the goodies, I quickly snatched up the box and ran inside ignoring my beast of a German shepherd.  As I ripped at the box with my keys, my dog was just as excited, apparent by his willingness to peel off the tape and sniff the box to ensure my safety!  At first glance I got the giggles and removed each piece, laying them neatly to the side. The package protection was ample and each piece secured soundly inside.


pump.jpgThe pump system looked fantastic, well designed, heavy duty and sort of a showpiece if you are into quality as I am.  I also dabble in track cars and engine mods so quality parts are irresistible to me.  I did notice one thing that concerned me which was the use of a rubber boot style connector, which is not bad for protection, but in my opinion not nearly as good in quality and durability as an IP (Ingress Protection Rating) rated Deutsch connector, but time will tell.


 COMPONENT UPDATE: After 2 years of use, perhaps 25 trips, the port solenoid failed. I know Bennett makes good pumps, and the failure on this is more than likely due to pulling in some saltwater after the port tab was pulled from the transom.  The Hewes is a no-wood transom, and the screws that came with the tabs certainly did not appear large enough, nor long enough.  I did question Bennett and they said it would be ok.  I went against my gut and lost a tab in a heavy storm.  My fault for not following my initial gut feeling.  I did install larger screws and shot some epoxy into the holes this time around. Overall the pump performed as expected with no issues.    


m120tab.jpgNext I removed the trim tabs and noticed instantly the one piece design with no welds to break or rust, a very nice weight indicating quality, and soft edges to eliminate line cut offs.  Nice touch!  The actuators were very lightweight, and all the hardware felt very sturdy. To say the least, I was impressed and couldn't wait to get these awesome looking tabs on my boat. Another thing I noticed here was the two 2 pin port and starboard wire connectors from the actuators (green & red) which contained very thin pins that plug into the control module.  Unfortunately, there isn't any quality way of sealing these since they plug into the module, and sit inside the module connection which I anticipate may be an issue (see EIC relay module below).  Again, I would have rather seen the use of a better IP rated connector, as well as a different connector, but time will tell. I do see some reasoning why the connections are so small here, as they must pass through a small hole in the transom, but other options could have been explored. 

 COMPONENT UPDATE: These tabs are phenomenal when it comes to control.  they grip the water and make your boat handle like never before.  They are well made and after 4 years showed no signs of rust or staining.  The actuators held up with no performance issues, but the sun did bleach them white within 6-8 months, so keep them covered, or perhaps put a UV blocker on them.  The connections are another story, as you'll see below.  

bennett_EIC_image.jpgNext I pulled out all the control units from their protective packaging and admired the control pads.  The soft touch rubber coatings and epoxy sealed backs were nothing short of a show piece that would soon blend in nicely next to my custom DSS keypads.  Running both port and starboard on the pad are a series of LED position indicators, yet another great touch of styling and a very useful feature. 

  COMPONENT UPDATE: I Had to replace this piece and the ATC tab control, as both dry-rotted in less than two years. The switch worked well, but often needed programmed for no apparent reason. Programming is just a matter of holding down the keys for a few seconds until it flashes, and then running the tabs up and down.  They worked after that, but multiple times per trip became a bit of an annoyance.  Overall, I'd say figure out how to keep them from dry-rotting and they are pretty good controls that certainly let you know the attitude of the boat at a glance.    



The EIC relay module is an epoxy potted sealed unit used in conjunction with the EIC control above.  As mentioned above in regards to the port and starboard actuator connections, this is the unit where those green and red wires connect to the corresponding colored fittings. Being an ex Navy electronics tech, and long time electronics component designer, I've had my fair share of designing cables and connectors in the marine and electronics industry, and have built many military grade connections. The problem I see here is that the module mounts on its back, leaving the connections open to any condensation setting in from above, via trickle down from the wires or just setting in from gravity.  The main power connection on the module (white 2 pin) is a male in terms of pin protrusion, but female in terms of casing, meaning that when you connect the two, the male casing (female connection being inserted) sits inside the Female casing (male connection), allowing any moisture to easily seep inside the connections. There is also no cover over either.  The 14 pin control cable connection on the module is a female and the male sits inside, as does the port and starboard connections, which allows moisture to seep in.  Personally, I would have liked to have seen all the connection points removed from the module and made to be external such as the colored wires you see above, rather than epoxy potted into the housing. At minimum, a reverse in the potted connections could have been made so that the connections coming into the module seat over the module connections, effectively shedding moisture  to the outside of the terminals.  Time will tell.

 COMPONENT UPDATE: I could not keep this unit working more than 6 months, despite being mounted in a cubby hole where no water could make direct contact.  However, I believe condensation formed, and, as stated above, seeped onto the connections. I constantly found the connection pins corroding, even with protection gel.  The ground post nut rusted and seized to the terminal post, thus I had to order a new unit, as the terminal spun when trying to free the nut.  Every connection that is potted into the unit corroded on both units.  After speaking with Bennett they said I needed to mount all the hardware under the center console, as the could not handle any moisture.  As much as I like Bennett, come on now, this is a marine product.  I have other products mounted in the same area, from battery ratchet straps, fuse holders, relays, battery switch, LED driver unit, etc, and they were not corroding.  The area was free from direct water contact, was high and dry, but being in the hull had some moisture.  I had some WalMart ratchet straps in there over 2 years that didn't lock up.  The issue is the thin metal of the pins not being able to handle any moisture whatsoever, in addition to the plug configuration and IP rating as mentioned above. 


altThis is the connector from the main cable running from the EIC control to the EIC relay module.  It is a 14 pin male casing with female inserts that seats flush to the male pins on the module.  As shown to the left, the first thing I noticed was that the heat shrink comes loose around the connector just by simply bending the wire a bit.  After inspection, a gentle tug reveals the wires inside and a straight open air connection to the modules pins for any moisture to find its way to.  This is a very poor marine connector and I suspect this plug to cause issues.  Also, you'll need to make sure to put a tension loop in this wire and secure it firmly.  The tolerance of this connection and its counterpart is nil, so when running this wire through your passages be sure to tape the ends to pad them or you'll find any nick will make it not fit.  This applies to the EIC control end as well.  Though this connector locks in place once seated, a little wiggle on the cable reveals a gap between the two connections that may let moisture in.  Time will tell.

  COMPONENT UPDATE: This plug corroded, worked its way loose, and constantly had issues maintaining connections. This plug should have been a female casing that slid over a male potted plug, and latched securely to keep it tight and sealed.    


Now that you got the jest of my mentality when it comes to new products, let's move on to the sea trial portion of this article. Keep in mind that even though I had a trim tab system previously, I did remove the old system entirely, and even had the through holes in the transom filled several weeks earlier when I had the boat restored.

The install was straight forward and very easy, as all the components are virtually plug-and-play, and only a few holes need to be drilled through the transom for the hydraulic tubing.  Additionally, a few leads and grounds need to be ran along with the cables to connect each component.  It's painless and shouldn't take more than a few hours depending on your boat and access to wiring canals below your deck.   Bennett's instructions are precise and laid out in a manner that is very easy to follow. In fact, I didn't even use the instructions, but I wouldn't recommend a novice to take this approach.

Sea Trial

"Get-up test"

As I motored slowly through the no wake zone out of Demands Landing, I fiddled with the controls a bit. The tabs moved up and down at a nice rate and were very quiet. The controls were responsive, and a subtle click could be felt with an easy press of the button, letting you know that you have engaged the switch.  The indicator LED's were plainly visible in direct sunlight even though they were mounted on a horizontal surface, which was one of my concerns when mounting the control.

Looking ahead, the break wall was nearing and my hand rode steadily on the throttle awaiting get up!  With my motor at zero tilt, I trimmed the tabs down 50% and stuck the throttle.  Instantly, the bow jumped up but held a very nice angle and within seconds I was on a plane and digging the bow.  That was a huge difference from my previous system, as my other tabs would have not come close to that kind of take off at 100% down trim.  For the next 20 minutes I played around with only the trim levels and found that 10-15% down trim had my boat running perfect at 50mph with no transom spooning or chiming whatsoever.

Now, the skinny water “get up” test; a test I've been dying to try.  With my previous tabs I often found myself roto-rooting the bottom on shallow water get-ups, often dragging the skeg in 3 feet of water with the motor in normal position from a dead float.   Sticking with the norm I ran the boat into 3 feet of water over a pure sand bottom and trimmed the tabs 100% down. I again stuck the throttle and cringed a bit as I anticipated the dreaded skeg drag. The initial transom drop looked as if it were going to follow suit to my old tabs, but as the tabs gulped down some water the transom responded vigorously in an upward kick that caused a little prop cavitation but did its job perfectly.

Taking another run at it, I upped the stakes and went for 2 feet of water, but this time I slowly gained speed until I could feel some resistive drag and then stuck the throttle and managed a flawless get up from 2 feet. When Bennett listed the tabs as having 30% more lift, I think they may have under estimated them a bit, as I'm sure I can get up in less water, but this is where I ended my test.  I nearly doubled my get up range, which to any flats angler is a major concern.  If I needed, I suppose I could possibly get up in 15 inches over mud bottom taking off in a circle and then straightening out, but until that day arrives we'll leave at a 2 foot clean get up, which is fine for me as I don't like tearing up flats.

"Stability Test"

I really had a great opportunity to test out the stability of the tabs while fishing with a few buddies along Redington beach. Winds were blowing about 12-20 out of the Northeast, which kept us protected running out of Blinds Pass and northward to Redington pier, but as the night progressed the winds began to pull around to the North and then out of the Northwest.  The tide and winds began to harmonize and soon kicked up some nice rollers, the kind that really gets your hull out of the water and seems to hold you high and dry for an extended period.

Becoming annoyed with the constant rolling we decided to head back.  I got up on plane quickly, and just as quickly had my fellow anglers crying out to back off the throttle for fear of tossing them overboard.  Paying respect to my fellow passengers, I had to turn to trim tab control and dial in a soft and dry ride for fear of seeing tears! If I were going to crawl through 3 -4 footers that were rolling in at a nasty angle, I'd have to get the boat trimmed like a finely tuned machine, and that I did.

I dropped the tabs to about 60%, and lowered the port side tab just a bit more to compensate for the extra weight and the waves pushing in from a starboard aft angle.  I throttled up and began plowing my way through the backside of the leading waves.  The bow was digging nicely and keeping us from going skyward, and as we climbed the backside, rode down the front and repeated, the tabs seemed to almost glue the stern to the water and kept the bow from over digging. I'm not sure exactly how this was achieved, but I expect this was a direct result of the concave format of the tabs.  Another usual scenario that occurs in water conditions like this is that the bow will constantly walk left to right making it hard to stay on a straight course at slow speeds.  However, this was not an issue, I believe due to the downward bend on the batwing tabs that serve as mini rudders much like surfboard fins, which kept the boat moving in a straight line.  My passengers were amazed at the ride, and repeatedly phrased, "this thing rides like a Cadillac!"

Having had the old flat tabs on and then switching to this new design really has given me a valuable insight.  Had I never experienced the flat tabs, I would not have actually known what a big difference the batwings really make.  I am truly amazed at the difference and could never imagine going back to a simple flat tab system, and definitely could not imagine running a boat without trim tabs.

Now to the brains and the one little piece that brings it all together for the most complete trim tab system available.

Auto Tab Control

At the time of this review, the auto tab control feature is just being released so I will not have that available for a few weeks.

Please stay tuned for the conclusion of this review as I put the complete system through heavy wave action, quick get ups, sharp turns, long turns, and anything else I can throw at it! I'm far from done and by the conclusion of this article you'll have had your first ride on Bennett's new state of the art trim tabs system.   I'll also have specs such as real number reaction times, and even underwater and on board video footage.

UPDATE: I was unable to ever get this feature working, though I really was looking forward to it, as this really appealed to me,  See below. 

UPDATE:  Mar 6, 2011 - To date I have not been able to finalize the install due to some component issues. I have been working with Bennett to resolve them.   I will be finishing the install and review in the very near future.  In addition to more details on the install and functions, I will give you my findings and thoughts on durability, product design, and the overall outcome.  

Stay Tuned and Happy Fishing... 

Conclusion: Oct, 2012 - I hate to give anyone a bad review, but I was unable to keep this system working, and never had all the components working at one time.  I gave up on all the bells and whistles and removed everything down to the pump, tabs, and a traditional rocker control, at which point it worked fine.  I did recently have another solenoid failure, and have yet to fix it, so I can't say for sure that the solenoids hold up or not.  To be honest, I'm tired of messing with it and moving on to try electric tabs.   The concept behind the system is great, but the design, in my opinion, wasn't well thought out for marine use.  All boats, especially flats boats, are going to have moisture, and if your product can't handle any moisture, then you may want to address that.  I'm not sure if Bennett Marine corrected any of these issues, as I did submit my opinions, so you may want to check on them before investing in a system.  Overall, I'd go with a basic system, keep it very dry, and keep an eye on the connections.  If you keep your boat under cover when not in use, the heat and condensation will build up and cause issues, so it's not just when you're boating.

I'm currently installing the UFlex trim tabs, so stay tuned for that review in the near future.    

Copyright © 2011