2010 170 SUPER SPORT: InstallingTrim Tab, SONAR Transducer

[seacatflx]

Q1: are owner-installed trim tabs unusual on smaller Boston Whaler boats?

Q2: what precautions are needed when attaching trim tabs to the transom or when routing cables from SONAR transducers through the transom of a Unibond hull?

Fig. 1. Suggested locations on transom of a 170 SUPER SPORT for mounting trim tabs (blue lines) and SONAR transducer (violet rectangle).

BW 170 Super Sport transom with markings 2.jpg (62.33 KiB) Viewed 3019 times

Q3: are the positions suggested in Figure 1 for a SONAR transducer [violet rectangle] and for trim tabs [the blue lines] appropriate?

BACKSTORY
I have a 2020 170 SUPER SPORT, and I am new to Boston Whaler boats. In 37 years I have had four boats, and three of them had trim tabs. I always had Bennett hydraulic trim tabs, but I think for the 170 SUPER SPORT that LENCO electric trim tabs would be easier to rig.

I think trim tabs would help the performance and ride [of my 2010 170 SUPER SPORT], especially in the chop that occurs on the shallow Banana River and Indian River lagoon when the wind comes up.

I realize I will probably have to lose the boarding ladder unless I used ZIPWAKE tabs, but they are expensive and aimed at much bigger boats.

[jimh]

Q2: what precautions are needed when attaching trim tabs to the transom,,,of a Unibond hull?

For advice on locations for installation of trim tabs to a Unibond hull, see the article in the REFERENCE section at

Trim Tab Installation
https://continuouswave.com/whaler/refer ... mTabs.html

and some follow-up comments on that article are available at

Trim Tab Installation (discussion)
https://continuouswave.com/ubb/Forum3/HTML/012417.html

ASIDE
The REFERENCE section is another part of the continuousWave website. The REFERENCE section contains long form articles that have been carefully researched and written and often illustrated on various topics related particularly to Boston Whaler boats and their unusual Unibond hull construction.

https://continuouswave.com/whaler/reference/

[jimh]

Q2: what precautions are needed when...routing cables from SONAR transducers through the transom of a Unibond hull?

For advice on mounting a SONAR transducer to the transom of a Unibond hull and routing of the cables associated with them, see

SONAR Transducers
https://continuouswave.com/whaler/refer ... ducer.html

[jimh]

Q1: are owner-installed trim tabs unusual on smaller Boston Whaler boats?

I am not aware of any particular data set that would indicate what percentage of "smaller" Boston Whaler boats have had trim tabs installed by their owners. I do not recall any factory options for trim tabs on Boston Whaler models in the 11 to 17-foot range, although, again, I have not specifically researched that topic.

As you acknowledge, in your situation with a 170 SUPER SPORT the installation of trim tabs might mean removal of the boarding ladder on the transom port side. Having a boarding ladder can be extremely useful in aiding swimmers to get onto the boat from the water, and, as an option, I suspect having a boarding ladder is enormously more common on "smaller" hulls than installing trim tabs. On that basis you might want to consider that removing a boarding ladder in order to install trim tabs might be considered very "unusual."

[Jefecinco]

Unless your 170 is underpowered trim tabs are not needed to improve the ride in chop. There is no reason to believe adding trim tabs to your boat will improve performance unless you are referring to the time required to get on plane. On smaller boats hull attitude is easily adjusted by adjusting engine trim. For improved hole-shot or time required to get on plane trimming the engine fully down should suffice unless the propeller is not designed for that purpose.

Boarding ladders are an important safety feature. If one needs to board the boat from deep water the ladder is very useful. To test this try boarding your boat from deep water on the starboard side of the transom.

[jimh]

I think trim tabs would help the...ride [of my 2010 170 SUPER SPORT], especially in...chop.

Typically in "chop" or short-spaced steep-wavefront seas, the desired trim is to have the bow slightly high. The outboard engine trim can usually alter the trim to maintain the bow at a higher than normal attitude into "chop", and moving crew weight from the bow will also help maintain the bow higher.

Generally "smaller" Boston Whaler boats will be sensitive to distribution of crew weight on the boat. Compensating for undesired trim attitudes can often by done by moving crew weight slightly. Even on my 24-foot Boston Whaler hull, I find that lateral trim can easily be adjusted by moving crew weight from side to side as necessary.

With regard to fore-and-aft trim, again moving crew weight will have a significant impact on trim on a smaller boat.

[fno]

There is a reason why you mostly see tabs on bigger boats, starting at 20'. But that is here nor there for the original poster. For a 17 Super Sport I would put a DoelFin on the cavitation plate. Just me. As for the transducer location, you will find problems with it so close to the tabs. find another spot on the transom with clear water underneath. Good luck

[seacatflx]

The installation of Bennett Bolt Trim Tabs has been completed. Bennet Support was very helpful. I also installed the Garmin GT-20 transducer.

Fig. 1. View of transom showing the installation of trim tabs.

Trim Tabs and transducer installed.jpg (139.17 KiB) Viewed 2179 times

I plan to test it this weekend.

[NorthShoreWhaler]

[The installation of trim tabs as seen in Figure 1] looks clean.

Q4: where are the wires to the tabs routed?

Q5: are the the wires to the tabs all the way through the transom and put in the rigging tube?

[jimh]

Q6: as seen in FIgure 1 above, why was the GT-20 SONAR transducer mounted so far from the centerline?

It looks like the transducer would be liable to be running in aerated water when the boat is on plane at speed.

Q7: are you experiencing any loss of the bottom echo when the boat is on plane?

[GoldenDaze]

I discussed adding trim tabs to my 160 Dauntless at https://continuouswave.com/forum/viewto ... 60&p=25738. It was a great upgrade.

-Bob

[seacatflx]

[The installation of trim tabs as seen in Figure 1] looks clean.

Q4: where are the wires to the tabs routed?

Q5: are the the wires to the tabs all the way through the transom and put in the rigging tube?

The wires go through the transom at the top of the actuators. Well sealed with 5200 per Bennett's recomendation. I know about 5200 vs 4200 buut went with Bennett's recomendation to be on the safe side. This will be the 4 th set of Bennett's I have owned over the years. Never had to remove them and I consider the tabs to be permanent.

[seacatflx]

Q6: as seen in FIgure 1 above, why was the GT-20 SONAR transducer mounted so far from the centerline?

GARMIN recommends a minimum spacing of the transducer from the centerline of the propeller of 15-inches. The trim tabs were at that location, so I did not have a lot of options. I will test next week when I launch the boat after the upgrades are done.

I am still finishing some electrical work.

[seacatflx]

I discussed adding trim tabs to my 160 Dauntless at https://continuouswave.com/forum/viewto ... 60&p=25738. It was a great upgrade.-Bob

Very nice write-up. This quote from your post is exactly what I am hoping to achieve:

"The results are fabulous. Minimum planing speed is reduced from 18 mph to about 15 mph, but more importantly, minimum "comfortable" speed with the boat solidly on plane and the bow down into chop was reduced from about 22 mph to 18 mph. She hops up on plane more quickly with a lot less bow rise, and up to about 32 mph the trim tabs do a great job flattening out the ride. Above that speed they're no longer useful, and when fully retracted they have no noticeable effect on boat speed.
My usual casual cruise speed is about 22-24 mph, and with the trim tabs extended "3 dots" I get a nice flat ride that cuts nicely through light chop or boat wakes.

I bought the 2010 Super Sport 170 in July 2026 with 500-hours on the engine. Since then I have:

• changed throttle-shift cables
• disassembled, cleaned, and lubricated the throttle control
• installed Baystar hydraulic steering
• installed new trim tabs
• installed a battery switch, bus bar, and cables for a new accessory subpanel, and
• installed a GARMIN 7-inch chart plotter-SONAR.

Still to be installed are a new Standard Horizon VHF Marine Band radio and GAM antenna.

And to top it all off, I am adding the OEM Boston Whaler bucket seats.

[GoldenDaze]

You've been busy! Sounds like you're making up a really nice boat.

[NorthShoreWhaler]

You will love the OEM bucket seats. I have them on my 150 Super Sport and they’re so comfortable.