Moderated Discussion Areas
ContinuousWave: Whaler Performance
|Author||Topic: trim tabs|
posted 04-07-2004 07:56 AM ET (US)
Anyone using Nauticus brand trim tabs? The literature describes them as doing everything but make your coffee.... Appears they're passive - with no controls needed. You adjust the pressure in the arms, and away you go. Claims include better hole shot, lower planing speed, higher top end, and better fuel economy. It would seem that based on the technology, some of these claims would have to be mutually exclusive. Too good to be true?
posted 04-07-2004 09:08 AM ET (US)
posted 04-07-2004 10:30 AM ET (US)
Moe, Thanks for the redirect. Only thing I diagreed with in the other thread was that you couldn't control the Nauticus tabs indepenently, therefore couldn't trim side to side. Actually, with one side lower than the other, that tab would compensate automatically. I do agree with the rest of the observations. If I can only jerk myself out of "frugal mode"...
posted 04-07-2004 01:08 PM ET (US)
Unless you have read something I haven't on the Nauticus website, the Nauticus tab would *not* compensate automatically if/when one side was lower than the other, unless the *same* side were always the low one, and the installer wound up the spring tighter on one side than on the other at installation. These things are made to work against the flow of the water more or less equally until water pressure from the increasing speed of the boat causes the tabs to push against the springs and become parallel with the underside of the boat; if they help anything, it is a better hole shot and lower speed planing. I don't see where they can do anything for differential and changing side to side "lean".
If Nauticus has become successful in getting one of two identical springs to automatically work harder against a greater force than the other spring does against a lesser force, with no intervening or auxiliary agency, they have achieved a big step towards that perpetual motion machine people talk about...
posted 04-07-2004 01:24 PM ET (US)
There's no free lunch when it comes to trim tabs. Either you pay up front for good ones that only produce drag when you need them, or you pay forever later with the automatic ones that are producing drag all the time.
posted 04-08-2004 09:35 AM ET (US)
Kingfish: Appreciate the observation. I was envisioning the behavior of these tabs thus: If the port side were deeper in the water than the starboard, then more area of that tab would also be in the water, so water pressure would be applied to a greater area of that tab compared to the other side which would have less area in the water. That condition would then result in more upward force on the side that had the tab deeper in the water, tending to eventually equalize the pressure on both tabs, and - simultaneously - trimming the port-starboard attitude. Of course, I don't really know much about the hydrodynamics of these things. My example would be to put your hand 2 inches into the water while moving forward in a boat, and then put it 6 inches into the water. The forces are very different. Guess this is why I'm not a physicist...
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