Re: manual trim question
Lazydawg,<br /><br />Rick is correct with regard to how the boat will perform when you change the trim angle. No matter what it is a comprimise, you will either get a better hole shot and run bow down at crusing speeds, or loose the hole shot and run correctly at cruising speeds. If you set it up for a heavy load (three people) you will need to adjust it for a lighter load ( one person). With electric tilt and trim you can adust the prop angle while underway. <br /><br />At this point you need to know that I have a proprietary interest in Smart Tabs, but I think you will find what I am about to say interesting.<br /><br />Trim tabs have not been commonly used on small boats for a few reasons which I will address, but nothing will work better than altering the hull design to compensate for load, speed, water conditions, etc. That is what trim tabs do. Just like flaps on airplane wings. With the Tabs down on take off, the stern lift will be amzing. When cruising you move the tabs up so the bow does not run down. <br /><br />This sounds like the same thing that the electric tilt trim will do, right? Nope! When using tilt trim to adjust the boat attitude your are using the prop to perform two functions, propell & correct attitude. Even if the prop was as efficient as trim tabs in correcting attitude (which it is not), running the prop through the water at an angle is not efficient from a thrust standpoint. The loss of efficiency is a loss of performance and fuel economy. Look at it this way; if the prop is facing streight up you have 0% efficiency ( no forward or backward thrust), if it is perpendicular to the surface of the water you have 100% efficiency (maximum thrust). Tilting the prop at any angle away from perpendicular is a loss of efficiency. Let the prop propell, and let the trim tabs do the attitude adjustment job.<br /><br />Now, why don't small boats come with trim tabs? First, hydraulic or electric trim tabs are too costly for the value of the boat, and with enough hp the boat will plane ( small boats typically have twice the power to weight ratio of their big brothers ( 30' sedan ).<br /><br />Secondly and most importantly is safety. If one trim tabs is accidentaly deployed on a small, light, fast boat at cruising speeds the passengers could end up in the water.<br /><br />Smart Tabs are designed specifically for smaller boats, and they are fully active / automatic at all times. Therefore the hull design is being adjusted to weight, speed, water conditions as they change. They are adjsutable to each individual boat to provide the maximum efficiency. Do a search on this site for Smart Tabs and read the comments.
