Schock Therapy wrote:I can see the appeal of high motoring speed when your boat is located some distance from decent sailing waters, although I thought that was why it was trailerable! ... I guess I am fortunate that I live in an area where I have to motor just long enough to get out of my slip, and I'm sailing! ... so forgive me if I am biased against the "powerboat mentality".
... 7kts upwind for a 26 foot boat sounds to me to be a slight exageration! Don't worry, I won't hold it against you! ... That is why I am skeptical about the performance claims some people are making!
Wow, ST ... too many points for discussion up there, so I've sliced it liberally.
First, I store my boat mast-up on the trailer at Alameda Marina - 6 miles downwind from the action. You can't really trail it anywhere and effectively gain sailing time, because SF Bay is not the friendliest place to put into - the time becomes lost in moving the boat, stepping the mast, etc. Store it nearer to the action and it's vastly more costly - no surprise. One Mac owner finally slipped his boat at Pier 39 for $350 per month. He later sold it and bought a keelboat, since economical storage (a Mac calling card) was no longer available. Candidly, it's pretty clear by looking at those beautiful pix that maybe you ARE spoiled!
I suspect MUCH of your objection to motoring is that diesel ... you haven't had the opportunity to motor quietly on a fuel-injected Suzuki, and no, they don't burn hundreds of gallons of fuel. At my best cruise speed (Suzuki-60 @ 3800 rpms) it's more like 3 gph @ 15 knots.
My Mac may have tacked through 90 w/ my dealer aboard, but I'm more likely to see 100 ... so, as for your reaching index, N/A in a Mac. Regarding speed upwind, Dave Gerr created a modified hull speed formula for semi-displacement boats. If you buy Dave's
modified hull speed theory (quoted here on a Potter owners website), you'll recognize that the Mac's flat hull could explain an adjusted hull speed of about 8 knots, largely due to her flat bottom. Not to say she's planing (which is impossible upwind anyhow) but she does not have any rounded hull to hold her within the typical wave pattern.
I've managed a close reach at 7+ knots on three different days on SF Bay. Each time was in whitecaps, heeled at 25*, jib and reefed main. Though it's annoying to your comrades at SA, my GPS reads in mph. On the first two days, it was a fluke to find the groove, and hold 7-to-8 mph for 10 minutes at a time before a roundup. On my third day though, I had it figured out. We managed to hold a port tack for 30 minutes, north-bound from Treasure Is. toward Angel Is, WNW winds of 18-20 kn in 2' chop. The boat felt like it was on rails, and the GPS read 8+ mph for that half-hour, kissing 9 mph a couple of times ... it never touched 7 mph once we gained speed on that tack. Currents on that wide stretch of the Bay are insignificant. You can do the math. That tack was such a rush that I was nearly onto the rocks off Angel Is before noticing, and easing up. I'm no expert, and this is my first sailboat. That's why it took me 3 years of reading and learning and several tries, and just the right conditions.
Also, I've modified my boat some. My mast is forward to 88*, which somewhat impairs pointing, but reduces rounding. The rig is very tight, since I don't need to step the mast each day. I have Garhauer rigid vang @ 12:1, which fractured the gooseneck casting on two of those 3 days. The day of a very long tack, I noticed the boom had a downward arc of ~ 2+ inches, before easing the vang. I have added an 8:1 split backstay and a 4:1 outhaul. I obviously had full ballast, motor disconnected from rudders (so its weight won't contribute to rounding), boom well downhill (not on centerline) and centerboard down at ~70 degrees (needs some aft centerboard to counter rounding). It would be much easier to duplicate with a traveler substituting for some of the excessive vang. I have Harken's small-boat windward sheeting car, but haven't decided how and where to mount it. Since upgrading to a UK 135 Genoa, I've never come close to those stats. The Genny is really a handful on any summer afternoon on SF Bay, but it does make downwind easier.
Several other Mac's have reported similar upwind results - even better - and I've stopped doubting it. I'm sure that you'd be even more competent to repeat my special days than I ... if you could tolerate the other frustrations of the Mac, you'd enjoy one heck of a ride.