Having read a number of discussion threads here at iboats.com, I am at a loss as to what would be the right choice of trim tabs for my boat. NautiJohn, Tabman, or anyone else - any advise would be appreciated!<br /><br />Here's a link to my type boat (hold the cursor over the thumbnail pic's to enlarge):<br /><br /> http://www.ibizaboats.no/baater.php?type=touring&gruppeid=491&id=galleri&navn=21touring&galleri=181 <br /><br />It's a 21 foot daycruiser, dry weight of about 2650 lbs, equipped with a 120 hp Mercruiser diesel, giving it a top speed of about 36 knots.<br /><br />The main problem is that it is under-powered and stern heavy, i.e. the stern digs in at any low speed, giving it a high planing treshold, a very high angle before planing, and the stern generally sits heavy in the water. In addition, being only 95 inches (240 cm) wide, the boat is sensitive to the sideways weight distribution.<br /><br />It needs at least 12-15 knots before planing, and cruises best at about 24 knots. However, this is a bit fast and skittish for the wife and kids, who would rather cruise comfortably along at 10-15 knots.<br /><br />By adding trim tabs, I was hoping to get a much lower planing speed, and a smoother and gentler ride in general. Also, I don't want to deal with anything complicated, and the ease of Smart Tabs or the Bennett ATC appeals to me.<br /><br />Now, after some rather lengthy research on the internet, I am still undecided. In your opinion, will the Smart Tabs do, or is my boat so large/heavy that it requires helm adjustable tabs?<br /><br />Any opinions on the QL boat trim system (using vertical interceptor planes rather than horisontal flaps, see www.qlmarine.com )? In particular, any views on whether or not these so called interceptors will give sufficient stern lift at low speeds?<br /><br />Finally, any views on the ATC or equivalent automatic systems (for example www.mente-marine.com )?<br /><br />I've also ordered a new Ballistic 21" SS propeller to replace the standard 23" pitch aluminium Black Max propeller, with the same objectives in mind.<br /><br />As you can tell, I am at a loss as to what to choose, but would very much want to find a solution that would not require switching to a larger and more stable boat.<br /><br />Any help would be appreciated!