[Bushwacker]

JohnB nailed the key issue regarding brackets - balance! When the 20' hull was designed in the 60's, the biggest OB's were the I-6 Merc & V-4 OMC's that weighed about 275-300 lbs. With that setup, the gas tank was centered right on the cg so trim didn't change with fuel load. I ran my Seafari for over 30 years with a 115 V-4; it cruised easily at about 20 kts with a heavy, 2-weeks-in-the-Bahamas type load, rode well and always felt well balanced. At the Anclote Key gathering in March, I asked Carl Moesly about the design parameters on the 20, and he said it was designed primarily for inshore use, unlike the 21, which was designed for offshore use (and racing!) with much less dynamic lift, so it would cut thru big seas w/o becoming airborne. The relatively light weight and low deadrise of the 20 shows up in head seas at or above about 3', because it will get airborne pretty easy if you run much over 20 kts. With a light motor and a lot of gear in the cabin, I found I could trim motor and tabs down and plane at 12-13 kts and ride very comfortably (sitting down) in 4 and even 5' head seas provided period was about 6 sec or more. This is a big deal when you're running 165 nm to the Abaco's! The only thing I didn't like was that open transom in big following seas! On my first (of 6) trip across the Gulf stream, we had winds of only 10 kts, but it clocked from NW->N->NE! We were about 30 miles out (middle of stream, max current) when wind was N - seas were 6-8' with an occasional breaker, and seemed to be only about 40-50' apart, steep enough that I was worried about stuffing the bow into the back of a big one and pitchpoling! I guarantee that most folks in those conditions will "get religion" if they haven't already done so! (MORAL: if there is ANY wind out of ANY northern quadrant, stay the hell out of the Gulf Stream!!)

Sure wished I had a solid transom at that time, so when I finally repowered last year, I had the transom closed in, picked bracket with most flotation and lightest & quietest motor I could find, the V-6 150(165!) E-Tec at 427 lbs. I probably would have bought the V-4 115(125) which is about 50 lbs lighter but they were not yet in production. Waterline is within about an inch of original and boat is still self bailing, so the big bracket maintains static balance provided you don't go nuts with engine weight. I believe the Seafari has more weight forward than the cc, so it probably will handle a bracket better than a cc also. When you're up on plane however, bracket flotation is gone and the boat KNOWS there is a bunch more weight on it's ass, located 30" further aft! I believe this tends to hurt the ride a little, but you can compensate with a good stern lifting prop. A 4 blade prop was a big improvement over 3B. The bracket allows you to raise motor a lot (My cav plate is about 4.5" above keel) and is probably worth 2-3 mph in top end. I've seen almost 50 mph which seems to be pretty good for a 150 on the 20' hull, although I care about ride much more than speed. It WILL start to porpoise if motor is trimmed out more than about 60% (0=full down, 100=full up). This condition is most efficiently corrected by changing thrust angle (motor trim); trim tabs will also do it, but they add drag as well as lift, so use power trim to change running angle and use the tabs for side-to-side balance! Just my .02 FWIW. Denny