Smart tabs

[Chi Man]

Looking at trim tabs for my Hardy Bosun, came across these, fully automatic http://www.nauticusinc.com/smart_tabsSX_automatic_trim_tabs.htm
Anybody got them or tried them?
The hardy is only 20 ft. long and not that fast (75hp o/b) but would like to get it a little more stable and get the bow down when at speed.
I had trim tabs on my previous boat and now I do not have them really notice the difference but want a simple answer and these automatic ones seem to fit the bill.
Thoughts form the MB forum?

 

[CLB]

I'm trying to get my head around how they work. The on,y thing I can thing is that they are sprung fully down and uses water pressure as the boat's speed increases to push them up. What happens if you want to go slow with a following sea? Are you going to be able to get the bow up or are the tabs going to be forcing it down leading to a wet ride?

 

[Nick_H]

I posted my experiences with them recently: http://www.ybw.com/forums/showthread.php?443387-New-Tender-Nauticus-Smart-Tabs&highlight=nauticus

In summary, they work really well even at lower speeds, you can compensate for the constant pressure of the tabs using the outboards power trim, and you can get a retractor kit that allows you to easily lift them in following seas.

 

[Chi Man]

thanks Nick, just read your post very helpful, and in the future will do a search on the forum before I post, nearly always someone has already answered my questions somewhere, a fountain of knowledge here.

 

[BruceK]

They do what they say on the tin, but they are not trim tabs in the conventional sense. They are an aide to getting the bow down to the correct angle and have the following benefits:
Lower plane speeds
Quicker to plane
Better low speed steering (assists against wander)
Stops porpoising (this is one area where they are better than trim tabs by having a shock absorbing nature)

Negatives:

Will have a slight impact on top speed. Usually about 2knts, possibly fuel consumption too

Arguable
Increases top speed by getting a better trim and negating any porpoising
Improves fuel economy by getting a better trim.
Can be used to correct a constant list (i.e. I had my port side smart tab slightly stiffer to correct a tendency of the boat to list to bort under power - torque effect)

If you have remote tilt and trim their benefits are not as revelationary but still quite useful. If your motor does not have remote tilt and trim they are a real boon for the price.

Totally my own opinion but at 20 foot you are starting to get out of their most practical range. Again in my own opinion in the 9 - 16 foot range is where they really excel. Not as good as trim tabs, but a whole lot better than no tabs.

Great things about them, the price and ease of fitment.

 

[rbcoomer]

I fitted them to our Fletcher as it had a heavy (60L) metal stern tank. Before fitting them, we had to hit about 22kts digging a huge hole before the bow dropped and she took off like a scalded cat! Not at at with anyone reasonably heavy in the back... I found this tricky for a family cruising boat as having a choice of a few knots or flat out wasn't really ideal...

After adding the Smart Tabs, we can now plane from about 12~13kts - although I have to push up to 15~16 and then ease back slightly. It's much more stable at higher speeds and more predictable, but does add a little drag I think. It has transformed the handling for the better. You can easily compensate with engine trim if you need to raise bow a bit. I have the tabs on the softest setting which is more than enough for our boat (15'9" with a 90HP Merc)

I'm trying to break through 40kts at the moment and after various pitch 3 and 4 bladed props all yielded a top end of around 36kts (plus the fact that the stern tank was a bit corroded), I'm currently fitting a bow tank instead. This will obviously upset all the balance again and I may find the tabs less effective/too much, but won't remove unless I have to.

I'd certainly use them again and think they're excellent value.

 

[lupa]

Had smart tabs on our boat when we bought it. Springs were slightly seazed on one side making the whole boat lop sided when planing. Took them off and binned em. More to go wrong and a lift out to fix