Trim tabs on Trawlers

[daviddraper]

I have an '06 Mainship. They call it a trawler only because it looks like one ... and I agree its strictly marketing that stole the term and it unfortunately takes away from the heavy displacement boats that run at true hull speeds - the true trawlers.
That said, I rarely travel more than about 7.5 knots except when I'm blowing out the turbo.
At 7.5 knots, the trim tabs are very effective for doing their intended job of 'trimming' when guest movement introduces unwelcome heeling. In the few times when I've wanted to run faster, I can't get close to the boat's top end without the tabs down.

 

[Jeanrouleau]

I have a marine trading Labelle 40, it is a 7 knot boat and has trim tabs. They work for me when my sister-in-law moves away from center to Starboard or Port.

I guess we have the same sister in law.....

 

[overgill]

I have a 32 Island Gypsy that I purchased 6 years ago it has factory installed double piston tabs that span the full with of the stern. I believe this is not an option and is still being installed on the 32 IG today. I keep them in working order but to be honest have never found a situation were I felt the need to use them.

When I purchased the boat I noticed that the tabs were fully deployed and painted in that position. During the sea trial with me at the wheel the PO started brining the RPM up as the speed increased the steering decreased. when I commented he replied that is why I don't run the boat over 8MPH. I never said anything about the tabs to him. This and a number of other misconceptions on the part of the PO save me a bunch of $$.

There is an old thread in hear that I chimed in on back when trying see if anyone else knew why IG install tabs on a 32 there were no definitive answers. It would be interesting to see if that has changed.

 

[Comodave]

Not trying to bust anyone’s chops, but if it has trims tabs it’s not a trawler.

Almost nobody here actually has a trawler if you really want to be absolutely correct.

 

[rslifkin]

Thinking about it, the benefit of tabs isn't just about speed. It also comes down to hull design and weight distribution. Some boats will benefit more than others even at the same speed because of those factors.

Other than a slight bit of systems complexity, I can't see a downside to having tabs if they make any difference at all on a specific boat.

 

[BruceK]

I have a 32 Island Gypsy that I purchased 6 years ago it has factory installed double piston tabs that span the full with of the stern. I believe this is not an option and is still being installed on the 32 IG today. I keep them in working order but to be honest have never found a situation were I felt the need to use them.

When I purchased the boat I noticed that the tabs were fully deployed and painted in that position. During the sea trial with me at the wheel the PO started brining the RPM up as the speed increased the steering decreased. when I commented he replied that is why I don't run the boat over 8MPH. I never said anything about the tabs to him. This and a number of other misconceptions on the part of the PO save me a bunch of $$.

There is an old thread in hear that I chimed in on back when trying see if anyone else knew why IG install tabs on a 32 there were no definitive answers. It would be interesting to see if that has changed.

I had no idea the IG32 is still being built, no new IGs sold here for years. My old 36 with Lehmans has no trim tabs,but I`ve seen them on higher powered 36s. Mine has a "wedge" extending about 2ft in from the transom, possibly factory I`m told, to keep the bow down.?similar function to trim tabs.

 

[lipets]

Not trying to bust anyone’s chops, but if it has trims tabs it’s not a trawler.

And what makes you the expert, RU a navel architect?


Recreational trawlers are pleasure boats which resemble fishing trawlers. They can also be called cruising trawlers or trawler yachts. Within the category, however, are many types and styles of vessels.
A fishing trawler for example, always has a displacement hull for load-carrying capacity. Recreational trawlers, on the other hand, are as likely to have a semi-displacement hull.


Recreational trawlers do in fact have trim tabs on some designs

 

[Mikala]

And what makes you the expert, RU a navel architect?


Recreational trawlers are pleasure boats which resemble fishing trawlers. They can also be called cruising trawlers or trawler yachts. Within the category, however, are many types and styles of vessels.
A fishing trawler for example, always has a displacement hull for load-carrying capacity. Recreational trawlers, on the other hand, are as likely to have a semi-displacement hull.


Recreational trawlers do in fact have trim tabs on some designs

If this makes you feel good...run with it.

 

[C lectric]

My notatrawler trawler of 32 ft with a semi displ. flat transom has trim tabs but not big ones . I thought what a waste when we first brought the boat home.

Although I can push my boat fully loaded to ~ 9knots I usually run at between 6.7 up to about 8.0 knots.

I soon learned that they did make a difference in the boats operation even at the 7K.

When full of fuel and water they helped noticeably reduce the wake and at the same engine rpm I could detect the sound of the engine unloading slightly.

I could see the bow rise angle alter, not a lot but noticeably.

They could help reduce the list leveling the boat between port and starboard.

When running light on fuel and water I had to back them off as they were enough to produce a slight bow steering effect.

In rough following seas the same, get off the tabs, and let the stern settle more and the handling difference was noticeable.

I'm sure that for many boats it won't make enough difference to make an installation worthwhile. For others it MAY help.

In my case it was the previous owner who installed them so they came with the boat. I simply learned to use them.

If your boat already has them then learn to use them effectively.

 

[JohnP]

Island Gypsy installed trim tabs on our 1996 36' Classic trawler. We normally cruise at 7.5 knots but with the help of a pair of 210hp 6bts we can also do 14knots. Fuel burn? I don't know, rarely run at that speed. Without using the tabs she will not plane.

 

[JohnP]

Our Island Gypsy 36 Classic has a deep forefoot and long full deep keel. She is well behaved and comfortable, but still has a reasonable turn of speed if needed.

 

[lipets]

Island Gypsy installed trim tabs on our 1996 36' Classic trawler. We normally cruise at 7.5 knots but with the help of a pair of 210hp 6bts we can also do 14knots. Fuel burn? I don't know, rarely run at that speed. Without using the tabs she will not plane.

John now you incriminated yourself, you don't have a trawler, going way too fast

 

[Aron Zions]

I would to know more of your thoughts on the Mainship 34. What style of navigation lights. Type of engine you had and any insight you can give me on Mainship.

 

[RickyD]

We have a Californian 55. 17.5 knot max. We have Bennet tabs. We carry about 500 feet of chain in the anchor locker and run a bit bow heavy. So I leave them in the up position.

 

[Gordon J]

We usually cruise at 8 - 8.5 knots. But if I need to kick it for s bridge opening, the tabs will get me to 15knots wot. Without tabs, wot is about 11 or so.

Gordon

 

[slowgoesit]

No, but your underwater hull shape does and vessel lineage says its not a trawler

The dictionary says its not a trawler
Quote:

trawler
/ˈtrɔːlə/
noun
noun: trawler; plural noun: trawlers
a fishing boat used for trawling.


A descriptive article here with the actual mechanics/design principles behind it

https://www.soundingsonline.com/news/what-makes-a-trawler-a-trawler

Interesting . . . I'm not sure why you are active on the "Trawler Forum" when your boat is obviously not a "fishing boat", and is no longer used for "trawling" , and therefore, by your own definition above . . . is no longer a trawler! But then who am I to judge?

 

[rslifkin]

I definitely make good use of my trim tabs. This is at 17 kts with a decent bit of tab down. With the tabs up, she'll struggle onto plane and run very bow-high with a massive wake and would never get anywhere near her 27kt top speed no matter how long you sit at WOT. Good use of trim makes a huge difference in speed and general boat feel.

My tabs are pretty big (I'll have to measure to confirm, but I think they're either 42x9 or 48x9) and capable of stuffing the bow down much further than you'd ever want to, so there's plenty of trim authority to sacrifice a bit of speed and trim down to flatten the wake (to about 2/3 of what's in the picture) when there's other boat traffic around.

Following seas require the bow trimmed up more, of course. But in my case, you still want some tab out, as otherwise the boat is just plowing along with the bow pointing to the sky. A good running attitude that keeps the bow up enough to not stuff it or bow steer still needs a little tab.

 

[markpierce]

Apparently, one needs to experiment with their tabs to see what works in and whatever conditions.

 

[Bob Cofer]

You kids and your modern boats!

 

[rslifkin]

Apparently, one needs to experiment with their tabs to see what works in and whatever conditions.

Absolutely. No 2 boats will behave quite the same.

 

[sunchaser]

What hypocrite you have a house boat down under


you better google a like better to support that weak argument.

Speaking of which, many houseboats have trim tabs and cruise quite nicely at 20 knots. But that doesn't make then a Swift Trawler. I'd guess Beneteau smiles at the "trawler" term discussions like this as marketing 101 is at play. BTW, has anybody yet seen Nordhavn officially refer to their vessels as trawlers?

The October 2019 issue of PMM has an article on Beebe philosophies and Seaton designs being planned for construction on the US East Coast. This effort is planned for at the Gladding Hearn yard where CRaymond Hunt design pilot boats are built. The article nicely dovetails into this thread.

 

[hollywood8118]

What the heck, today we are forced to accept so many different names regarding gender ( I'm a dinosaur and still think there are two! ) why not just keep calling the "style" of boats we are all here to discuss TRAWLERS!


HOLLYWOOD

 

[dhays]

What the heck, today we are forced to accept so many different names regarding gender ( I'm a dinosaur and still think there are two! ) why not just keep calling the "style" of boats we are all here to discuss TRAWLERS!


HOLLYWOOD

Because that would make way too much sense. Why go along with the generally accepted term used by the TF community (yeah, we know what we mean when we say “trawler”) when someone can argue a pointless point in an attempt to prove a point?

 

[hollywood8118]

Talk about confused.

I get that way when someone calls a trawler a motor cruiser.
HW

 

[RossWilson]

Let's differentiate between 'classic' trawlers and 'modern' trawlers. My 2006 Mainship T is equipped with 4 tabs, and I use them regularly to help plane and improve speed. With twin Yanmars, she cruises comfortably at 10-12 knots, and can max out around 20 knots. At either speed, the tabs definitely lower the bow and increase speed by 1-3 knots. Maybe the forward-positioned single fuel tank makes a difference?

 

[Simi 60]

Interesting . . . I'm not sure why you are active on the "Trawler Forum" when your boat is obviously not a "fishing boat", and is no longer used for "trawling" , and therefore, by your own definition above . . . is no longer a trawler! But then who am I to judge?

You did read the rest of the description describing a trawler hull shape and characteristics right?

Nav, I guess not.

 

[lipets]

Not sure why you keep up with your diatribe



that article said


"Precision wouldn’t suffer if use of the word “trawler” were expanded somewhat in the yachting world. Perhaps we should call boats like the Nordhavn 47 “offshore trawler yachts” to distinguish them from “coastal trawler yachts.”


So there are two types pointed to in that article,

you have an issue with that classification?

 

[w8n4sun]

I like our boat.

 

[Benchmark]

My other boat is an Ocean Alexander 423 n"trawler" at 34,000 lbs, with only 420 total HP from a pair of 3208 Cat Naturals, and will plane at 13 Kn, due exclusively to the use of trim tabs with the throttles in the kitchen.......yes, they help, up to you to figure it out....more control of attitude gives you best speed or best fuel economy. They do, do something.

 

[rslifkin]

To follow up, now that we're hauled for the season, I measured my tabs at 48x12. In other words, oversized according to the standard Bennett recommendations. But that's not a bad thing IMO.

Size relative to the transom is shown here: