Boating - Trim Tabs/Power Tilt
Discussion
Basically because an outboard should always be trimmed for the most efficient propulsion in the intended direction
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If one uses their outboards trim to pitch the boat so it planes earliest, that's the best thing to use the trim on the outboard for.
Trim tabs, assuming you mean separate units independent of the engines, but with their own hydraulic rams are more intended to set the boat up on longer passages - when for example a cross-wind causes the boat to lean to port for example, you can dip you port tab a bit which lift / effectively rolls the boat back to starboard.
Trim tabs correct these fine balance issues with far less drag and wasted enrgy than pointing your port engine's prop at the sea bed....
I hope I have explained that ok, though I am not at all sure I have....
Cheers - Nick.
.
If one uses their outboards trim to pitch the boat so it planes earliest, that's the best thing to use the trim on the outboard for.
Trim tabs, assuming you mean separate units independent of the engines, but with their own hydraulic rams are more intended to set the boat up on longer passages - when for example a cross-wind causes the boat to lean to port for example, you can dip you port tab a bit which lift / effectively rolls the boat back to starboard.
Trim tabs correct these fine balance issues with far less drag and wasted enrgy than pointing your port engine's prop at the sea bed....
I hope I have explained that ok, though I am not at all sure I have....
Cheers - Nick.
Kind of!
Basically what I am saying is the the trim on the engines / outdrive legs are for nose up/nose down trim, and the separate tabs (usually position much closer to the back corners for maximum effectivness are for lateral adjustment or roll because of a strong cross wind which is making the boat roll to leward for example.
The separate tabs are as much for making the boat level and comfortable as they are for performance. though if a boat is going forward on the pi$$ due to a side wide, the drag this causes is likely to be suitably bad that adding more drag / correcting the rolls by dipping the appropriate tab is the lesser of two evils so to speak....
Basically what I am saying is the the trim on the engines / outdrive legs are for nose up/nose down trim, and the separate tabs (usually position much closer to the back corners for maximum effectivness are for lateral adjustment or roll because of a strong cross wind which is making the boat roll to leward for example.
The separate tabs are as much for making the boat level and comfortable as they are for performance. though if a boat is going forward on the pi$$ due to a side wide, the drag this causes is likely to be suitably bad that adding more drag / correcting the rolls by dipping the appropriate tab is the lesser of two evils so to speak....
Nico is pretty well spot on. Think of it as engine trim is for efficiency and tabs are for comfort.
So as well as correcting heel you may also find in say a head sea that the boat will ride better if the nose is pointed down slightly whilst maintaining the driveline parallel with the boat bottom. Conversely in a following sea you may want to trim the engines out slightly to stop the nose burying every time you come down a wave.
Whereas on a flat sea you may benefit from trimming the engines out slightly to get the boat running on as little surface area as possible for speed.
And if you are running at non planing speed you may want to get the nose down rather than the sit up and beg attitude, while you could achieve that by trimming the engines right in this has the effect of lifting the stern and making the boat steer around the nose. Much better to drop both tabs in and maintain the engines in the most efficient trim.
So as well as correcting heel you may also find in say a head sea that the boat will ride better if the nose is pointed down slightly whilst maintaining the driveline parallel with the boat bottom. Conversely in a following sea you may want to trim the engines out slightly to stop the nose burying every time you come down a wave.
Whereas on a flat sea you may benefit from trimming the engines out slightly to get the boat running on as little surface area as possible for speed.
And if you are running at non planing speed you may want to get the nose down rather than the sit up and beg attitude, while you could achieve that by trimming the engines right in this has the effect of lifting the stern and making the boat steer around the nose. Much better to drop both tabs in and maintain the engines in the most efficient trim.
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