I figure my M-17 ought to do a little over 5.3 knots, based on its waterline length. But at the recent Florida 120, my GPS indicated 5.5 to 5.8 knots for periods long enough to make me wonder how it was possible. We were fairly close hauled, heeling 20°, to 30° in the gusts. Does this boat grow when heeled? Oh it was fun! Mark House "Seranita"
In a fresh breeze sailing wing-and-wing I've clocked a little over six knots. I remember seeing somewhere that the M-17 is a "semi-displacement" hull which can slightly exceed its theoretical maximum. Any naval architects out there that can shed more light on this? Rick M-17 #633 Lynne L On Tue, May 24, 2011 at 10:00 AM, Mark House <itsmark@bresnan.net> wrote:
I figure my M-17 ought to do a little over 5.3 knots, based on its waterline length. But at the recent Florida 120, my GPS indicated 5.5 to 5.8 knots for periods long enough to make me wonder how it was possible. We were fairly close hauled, heeling 20°, to 30° in the gusts. Does this boat grow when heeled? Oh it was fun!
Mark House "Seranita" _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
When posting, remember that there is no privacy on the Internet!
I figure my M-17 ought to do a little over 5.3 knots, based on its waterline length. But at the recent Florida 120, my GPS indicated 5.5 to 5.8 knots for periods long enough to make me wonder how it was possible. We were fairly close hauled, heeling 20°, to 30° in the gusts. Does this boat grow when heeled? Oh it was fun!
I commonly sail 5+knots close hauled. Though I generally find it will go faster when flatter. 10-15 degrees. I once kept 6.5 on the clock for about 20 seconds. Surfing down a long wave on a broad reach with a little more sail than I should have had up. Everything including me was maxed out and too much. Such is the magic of the 17.
Yes, the M15 and M17 are semi-displacement hull, so they can go faster than a displacement hull. They can also get a super-charged boost when surfing, and go almost-scary fast. Take a look here for an explanation: http://www.blumhorst.com/potterpages/hullspeed.html . Boat LWL (ft) Disp D/L S/L Disp HullSpeed True HullSpeed True Hullspeed with cargo Potter 15 12.00 475 123 1.85 4.6 knots 6.4 knots 4.8 knots w 700# Potter 15 12.00 475 123 1.85 4.6 knots 6.4 knots 5.2 knots w 450# Potter 19 16.25 1300 135 1.80 5.4 knots 7.2 knots 6.3 knots w 700# Montgomery 15 13.25 750 144 1.76 4.6 knots 6.4 knots 5.2 knots w 700# Montgomery 17 15.83 1600 180 1.64 5.3 knots 6.5 knots 5.8 knots w 700# Compac 19 16.33 2000 205 1.58 5.4 knots 6.4 knots 5.8 knots w 700# Judy Blumhorst Hyde Sails USA, Northern California judyb@hydesailsUSA.com cell: 925.997.0786 fax: 925.820.2327 skype: judith.blumhorst www.HydeSails.com/NorthAmerica ________________________________ From: Tim Diebert <tim@timtone.com> To: For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Sent: Tue, May 24, 2011 7:19:14 AM Subject: Re: M_Boats: Max Speed “I figure my M-17 ought to do a little over 5.3 knots, based on its waterline length. But at the recent Florida 120, my GPS indicated 5.5 to 5.8 knots for periods long enough to make me wonder how it was possible. We were fairly close hauled, heeling 20°, to 30° in the gusts. Does this boat grow when heeled? Oh it was fun!”
I commonly sail 5+knots close hauled. Though I generally find it will go faster when flatter. 10-15 degrees. I once kept 6.5 on the clock for about 20 seconds. Surfing down a long wave on a broad reach with a little more sail than I should have had up. Everything including me was maxed out and ‘too much’. Such is the magic of the 17.
_______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats When posting, remember that there is no privacy on the Internet!
Thanks, Judy! your formulae predict exactly what I observed. We were loaded for 4 days camping, thea normal waterlien submerged. Mark House ----- Original Message ----- From: "Judith Blumhorst, DC" <drjudyb@blumhorst.com> To: "For and about Montgomery Sailboats" <montgomery_boats@mailman.xmission.com> Sent: Tuesday, May 24, 2011 8:42 AM Subject: Re: M_Boats: Max Speed
Yes, the M15 and M17 are semi-displacement hull, so they can go faster than a displacement hull. They can also get a super-charged boost when surfing, and go almost-scary fast.
Take a look here for an explanation:
http://www.blumhorst.com/potterpages/hullspeed.html .
Boat LWL (ft) Disp D/L S/L Disp HullSpeed True HullSpeed True Hullspeed with cargo
Potter 15 12.00 475 123 1.85 4.6 knots 6.4 knots 4.8 knots w 700# Potter 15 12.00 475 123 1.85 4.6 knots 6.4 knots 5.2 knots w 450# Potter 19 16.25 1300 135 1.80 5.4 knots 7.2 knots 6.3 knots w 700# Montgomery 15 13.25 750 144 1.76 4.6 knots 6.4 knots 5.2 knots w 700# Montgomery 17 15.83 1600 180 1.64 5.3 knots 6.5 knots 5.8 knots w 700# Compac 19 16.33 2000 205 1.58 5.4 knots 6.4 knots 5.8 knots w 700#
Judy Blumhorst Hyde Sails USA, Northern California judyb@hydesailsUSA.com cell: 925.997.0786 fax: 925.820.2327 skype: judith.blumhorst www.HydeSails.com/NorthAmerica
________________________________ From: Tim Diebert <tim@timtone.com> To: For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Sent: Tue, May 24, 2011 7:19:14 AM Subject: Re: M_Boats: Max Speed
“I figure my M-17 ought to do a little over 5.3 knots, based on its waterline length. But at the recent Florida 120, my GPS indicated 5.5 to 5.8 knots for periods long enough to make me wonder how it was possible. We were fairly close hauled, heeling 20°, to 30° in the gusts. Does this boat grow when heeled? Oh it was fun!”
I commonly sail 5+knots close hauled. Though I generally find it will go faster when flatter. 10-15 degrees. I once kept 6.5 on the clock for about 20 seconds. Surfing down a long wave on a broad reach with a little more sail than I should have had up. Everything including me was maxed out and ‘too much’. Such is the magic of the 17.
_______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
When posting, remember that there is no privacy on the Internet! _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
When posting, remember that there is no privacy on the Internet!
Thanks, Judy, that's a good explanation. I've exceeded hull speed, but since I sail on a river (the Potomac) I don't get to surf. Sounds like fun! Rick M-17 #633 Lynne L -- Sent from my Palm Pre On May 24, 2011 10:42 AM, Judith Blumhorst, DC <drjudyb@blumhorst.com> wrote: Yes, the M15 and M17 are semi-displacement hull, so they can go faster than a displacement hull. They can also get a super-charged boost when surfing, and go almost-scary fast. Take a look here for an explanation: http://www.blumhorst.com/potterpages/hullspeed.html . Boat LWL (ft) Disp D/L S/L Disp HullSpeed True HullSpeed True Hullspeed with cargo Potter 15 12.00 475 123 1.85 4.6 knots 6.4 knots 4.8 knots w 700# Potter 15 12.00 475 123 1.85 4.6 knots 6.4 knots 5.2 knots w 450# Potter 19 16.25 1300 135 1.80 5.4 knots 7.2 knots 6.3 knots w 700# Montgomery 15 13.25 750 144 1.76 4.6 knots 6.4 knots 5.2 knots w 700# Montgomery 17 15.83 1600 180 1.64 5.3 knots 6.5 knots 5.8 knots w 700# Compac 19 16.33 2000 205 1.58 5.4 knots 6.4 knots 5.8 knots w 700# Judy Blumhorst Hyde Sails USA, Northern California judyb@hydesailsUSA.com cell: 925.997.0786 fax: 925.820.2327 skype: judith.blumhorst www.HydeSails.com/NorthAmerica ________________________________ From: Tim Diebert <tim@timtone.com> To: For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Sent: Tue, May 24, 2011 7:19:14 AM Subject: Re: M_Boats: Max Speed “I figure my M-17 ought to do a little over 5.3 knots, based on its waterline length. But at the recent Florida 120, my GPS indicated 5.5 to 5.8 knots for periods long enough to make me wonder how it was possible. We were fairly close hauled, heeling 20°, to 30° in the gusts. Does this boat grow when heeled? Oh it was fun!” >I commonly sail 5+knots close hauled. Though I generally find it will go faster when flatter. 10-15 degrees. I once kept 6.5 on the clock for about 20 seconds. Surfing down a long wave on a broad reach with a little more sail than I should have had up. Everything including me was maxed out and ‘too much’. Such is the magic of the 17. _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats When posting, remember that there is no privacy on the Internet! _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats When posting, remember that there is no privacy on the Internet!
participants (5)
-
John Davies -
Judith Blumhorst, DC -
Mark House -
Rick Davies
-
Tim Diebert