Bainbridge Currents for Sept 12, 2015
|
Tom Kreyche
Here's my take on the tidal currents for next Saturday's race. I'm interested to hear other opinions. ...Tom Kreyche Sources Overview Without taking wind into consideration, a CCW direction will almost certainly be more favorable. If there is a South wind, CCW will certainly be preferred since the East side of the island is more exposed to the wind and it will be a downwind leg. Racers may wish to consider a CW direction if there is a strong North wind. This would take advantage of a downwind leg on the East side of the island, but racers would face opposing the tidal currents.
With a 9:30 a.m. start time, racers will enter the Passage at around 9:50 a.m. They will face a 1 kt ebb tide at the North end, at the same time there is 2 kt ebb at the South end. The current will be decreasing rapidly so the trip through the Passage should get easier rather than more difficult. During the leg along the West side of the Island, there will be a transition from a weak ebb at the N end to a weak flood towards the S end. Earlier arrivals at Rich Passage will take better advantage of the weak .5 to 1 kt ebb, since it weakens fairly rapidly and goes slack at 11:29 a.m. to noon. Clockwise This is less favorable than counter-clockwise. Racers headed South on the East side of Bainbridge will be facing a weak ebb tide. Rich Passage goes slack at 11:29 a.m. to noon – earlier arrivals will also face a weak ebb through the Passage. A greater problem occurs approaching Agate Passage, where the flood will be increasing rapidly and peaking at 4.2 kt at 2:10 p.m. Racers will typically be facing a 3 kt or greater flood. The earlier arrival the better. Tidal Currents Max Current -2 kt (ebb) at 7:44 a.m. Slack Water 10:45 a.m. Max Current +1.7 kt 2:03 p.m.
Max Current -3.9 kt (ebb) at 7:56 a.m. Slack Water 10:48 p.m. Max Current 4.2 kt (flood) 2:10 p.m.
Max Current -3.4 kt (ebb) at 9:05 a.m. Slack Water 11:29 a.m. Max Current +3.2 kt (flood) at 2:55 p.m.
Max Current -3.1 kt (ebb) at 9:26 a.m. Slack Water 11:59 a.m. Max Current 1.7 kt (flood) at 2:48 p.m. |
|
|
|
Debbie Natelson
Thanks Tom! Great analysis. So nice of you to share. I have a sched conflict and may not be able to make this years Bainbridge race :( -- but have a great one all who do get to do one of my favorite races. Always a challenge, no matter which way you go. Debbie On Mon, Sep 7, 2015 at 6:10 PM, tkreyche@... [SoundRowers] <SoundRowers-noreply@...> wrote:
|
|
|
|
Steve Bennett
Thanks Tom, for a more thorough analysis than you would have gotten from me. I totally concur with your call. Here is my read:
Look forward to seeing you all on Saturday. We'll have the usual soup and bread at the finish, also a nice selection of commemorative hats, thanks to Stoneway Concrete. Tide charts attached, I think. Steve From: "tkreyche@... [SoundRowers]" To: SoundRowers@... Sent: Monday, September 7, 2015 6:10 PM Subject: [SoundRowers] Bainbridge Currents for Sept 12, 2015 Here's my take on the tidal currents for next Saturday's race. I'm interested to hear other opinions. ...Tom Kreyche Sources http://www.deepzoom.com/index.html https://tidesandcurrents.noaa.gov/currents15/tab2pc2.html#17 Overview Without taking wind into consideration, a CCW direction will almost certainly be more favorable. If there is a South wind, CCW will certainly be preferred since the East side of the island is more exposed to the wind and it will be a downwind leg. Racers may wish to consider a CW direction if there is a strong North wind. This would take advantage of a downwind leg on the East side of the island, but racers would face opposing the tidal currents. Counter-Clockwise With a 9:30 a.m. start time, racers will enter the Passage at around 9:50 a.m. They will face a 1 kt ebb tide at the North end, at the same time there is 2 kt ebb at the South end. The current will be decreasing rapidly so the trip through the Passage should get easier rather than more difficult. During the leg along the West side of the Island, there will be a transition from a weak ebb at the N end to a weak flood towards the S end. Earlier arrivals at Rich Passage will take better advantage of the weak .5 to 1 kt ebb, since it weakens fairly rapidly and goes slack at 11:29 a.m. to noon. Clockwise This is less favorable than counter-clockwise. Racers headed South on the East side of Bainbridge will be facing a weak ebb tide. Rich Passage goes slack at 11:29 a.m. to noon – earlier arrivals will also face a weak ebb through the Passage. A greater problem occurs approaching Agate Passage, where the flood will be increasing rapidly and peaking at 4.2 kt at 2:10 p.m. Racers will typically be facing a 3 kt or greater flood. The earlier arrival the better. Tidal Currents Agate Passage N End - Flood Direction, 230 True, Ebb (-) Direction, 032 True Max Current -2 kt (ebb) at 7:44 a.m. Slack Water 10:45 a.m. Max Current +1.7 kt 2:03 p.m. Agate Passage S End - Flood Direction, 216 True, Ebb (-) Direction, 037 True Max Current -3.9 kt (ebb) at 7:56 a.m. Slack Water 10:48 p.m. Max Current 4.2 kt (flood) 2:10 p.m. Rich Passage W End - Flood Direction, 238 True. Ebb (-) Direction, 055 True Max Current -3.4 kt (ebb) at 9:05 a.m. Slack Water 11:29 a.m. Max Current +3.2 kt (flood) at 2:55 p.m. Rich Passage Off Pleasant Beach Max Current -3.1 kt (ebb) at 9:26 a.m. Slack Water 11:59 a.m. Max Current 1.7 kt (flood) at 2:48 p.m. |
|
|
|
Steve Bennett
So then, with the start now at Fort Ward, our hat is cocked; the tables turned. Here's my new read: Leaving Fort Ward, clockwise, within an hour of slack, a 5 hour racer should arrive at the Agate Pass Bridge with a favorable current of 2 kt, and slower paddlers will benefit even more. Had he opted for counter-clockwise he would be fighting 3.5 kt at the bridge. There'll likely be no contrarians this year. Also for your planning: ·
It is 15 miles from Fort Ward to the Agate Pass Bridge
counterclockwise.
·
It is 11 miles from Fort Ward to the Agate Pass Bridge
clockwise
·
Halfway is at about the middle of the big bay that extends
from Agate Point to Point Monroe (which is just around the corner to the north from Fay Bainbridge) Any other thoughts ? Steve From: Steve Bennett To: "tkreyche@..." ; "SoundRowers@..." Sent: Tuesday, September 8, 2015 11:33 AM Subject: Re: [SoundRowers] Bainbridge Currents for Sept 12, 2015 Thanks Tom, for a more thorough analysis than you would have gotten from me. I totally concur with your call. Here is my read:
Look forward to seeing you all on Saturday. We'll have the usual soup and bread at the finish, also a nice selection of commemorative hats, thanks to Stoneway Concrete. Tide charts attached, I think. Steve From: "tkreyche@... [SoundRowers]" To: SoundRowers@... Sent: Monday, September 7, 2015 6:10 PM Subject: [SoundRowers] Bainbridge Currents for Sept 12, 2015 Here's my take on the tidal currents for next Saturday's race. I'm interested to hear other opinions. ...Tom Kreyche Sources http://www.deepzoom.com/index.html https://tidesandcurrents.noaa.gov/currents15/tab2pc2.html#17 Overview Without taking wind into consideration, a CCW direction will almost certainly be more favorable. If there is a South wind, CCW will certainly be preferred since the East side of the island is more exposed to the wind and it will be a downwind leg. Racers may wish to consider a CW direction if there is a strong North wind. This would take advantage of a downwind leg on the East side of the island, but racers would face opposing the tidal currents. Counter-Clockwise With a 9:30 a.m. start time, racers will enter the Passage at around 9:50 a.m. They will face a 1 kt ebb tide at the North end, at the same time there is 2 kt ebb at the South end. The current will be decreasing rapidly so the trip through the Passage should get easier rather than more difficult. During the leg along the West side of the Island, there will be a transition from a weak ebb at the N end to a weak flood towards the S end. Earlier arrivals at Rich Passage will take better advantage of the weak .5 to 1 kt ebb, since it weakens fairly rapidly and goes slack at 11:29 a.m. to noon. Clockwise This is less favorable than counter-clockwise. Racers headed South on the East side of Bainbridge will be facing a weak ebb tide. Rich Passage goes slack at 11:29 a.m. to noon – earlier arrivals will also face a weak ebb through the Passage. A greater problem occurs approaching Agate Passage, where the flood will be increasing rapidly and peaking at 4.2 kt at 2:10 p.m. Racers will typically be facing a 3 kt or greater flood. The earlier arrival the better. Tidal Currents Agate Passage N End - Flood Direction, 230 True, Ebb (-) Direction, 032 True Max Current -2 kt (ebb) at 7:44 a.m. Slack Water 10:45 a.m. Max Current +1.7 kt 2:03 p.m. Agate Passage S End - Flood Direction, 216 True, Ebb (-) Direction, 037 True Max Current -3.9 kt (ebb) at 7:56 a.m. Slack Water 10:48 p.m. Max Current 4.2 kt (flood) 2:10 p.m. Rich Passage W End - Flood Direction, 238 True. Ebb (-) Direction, 055 True Max Current -3.4 kt (ebb) at 9:05 a.m. Slack Water 11:29 a.m. Max Current +3.2 kt (flood) at 2:55 p.m. Rich Passage Off Pleasant Beach Max Current -3.1 kt (ebb) at 9:26 a.m. Slack Water 11:59 a.m. Max Current 1.7 kt (flood) at 2:48 p.m. |
|
|
|
Tom Kreyche
Steve,
Here’s my revised analysis based on a start at Ft. Ward at about 9:45 and a 4 hour racer. This disagrees with yours a fair bit, except we’re both suggesting CW would be best if the predicted N wind sticks.
Any other opinions?
…Tom
Overview This estimate is for Saturday September 12, with racers starting from Fort Ward. Without considering wind, CCW may be more favorable since racers will spend less time fighting the current in Rich Passage. CCW may also have a slight advantage with the current through Agate Passage. However winds are forecast to be out of the N, which would tip the balance towards CW direction. The 9-mile E side of the island is exposed and a downwind leg is preferred.
Counter-Clockwise A 3kt ebb will push racers to a quick exit from Rich Passage. On the S and SE end of the island a weak ebb will be beneficial. By the time racers reach Agate Passage (11 miles from the start) at about 11:15 a.m., they will be aided by a weak but building flood of 1.5 to 2kt. The current will aid racers on the NW side of the island, and transition to hindering them on the SW side as the flood into Rich Passage takes effect. A 2kt flood tide will hinder the entrance into Rich Passage with it weakening to 1kt near Ft. Ward.
Clockwise Racers will immediately face a 3kt ebb through Rich Passage, and will also be hindered around the SW side of the island. The W and NW should be mostly slack. The entrance into Agate Passage is about 15 miles from the start - it is slack at 10:47 and builds rapidly to flood. Early arrivals will see slack or a light flood, but later arrivals will face 1.5 by 11:30 a.m. A weak flood will aid racers on the E side of the island and back into Rich Passage. One strategy would be to work hard the first part of the race to get out of Rich Passage and through Agate early, then cruise downwind on the E side of the island.
Tidal Currents Max Current -2 kt (ebb) at 7:44 a.m. Slack Water 10:45 a.m. Max Current +1.7 kt 2:03 p.m.
Max Current -3.9 kt (ebb) at 7:56 a.m. Slack Water 10:48 p.m. Max Current 4.2 kt (flood) 2:10 p.m.
Max Current -3.4 kt (ebb) at 9:05 a.m. Slack Water 11:29 a.m. Max Current +3.2 kt (flood) at 2:55 p.m.
Max Current -3.1 kt (ebb) at 9:26 a.m. Slack Water 11:59 a.m. Max Current 1.7 kt (flood) at 2:48 p.m.
Sources
From: Steve Bennett [mailto:bennett_seattle@...]
Sent: Wednesday, September 09, 2015 4:43 PM To: tkreyche@...; SoundRowers@... Subject: Re: [SoundRowers] Bainbridge Currents for Sept 12, 2015
So then, with the start now at Fort Ward, our hat is cocked; the tables turned. Here's my new read:
Leaving Fort Ward, clockwise, within an hour of slack, a 5 hour racer should arrive at the Agate Pass Bridge with a favorable current of 2 kt, and slower paddlers will benefit even more. Had he opted for counter-clockwise he would be fighting 3.5 kt at the bridge. There'll likely be no contrarians this year.
Also for your planning:
· It is 15 miles from Fort Ward to the Agate Pass Bridge counterclockwise. · It is 11 miles from Fort Ward to the Agate Pass Bridge clockwise · Halfway is at about the middle of the big bay that extends from Agate Point to Point Monroe (which is just around the corner to the north from Fay Bainbridge) Any other thoughts ?
Steve |
|
|
|
Steve Bennett
Tom,
Nice work. I defer to your analysis. You have caught my
error: I either foolishly or mistakenly
equated the flood at Agate and Rich. Slack at Rich is over an hour later at
noon. The tide is at ebb in Rich until then.
I think the Counter-Clockwise
distance to Agate Bridge from Fort Ward is 15 miles, however.
Steve From: "'Tom Kreyche' tkreyche@... [SoundRowers]" To: 'Steve Bennett' ; SoundRowers@... Sent: Wednesday, September 9, 2015 10:47 PM Subject: RE: [SoundRowers] Bainbridge Currents for Sept 12, 2015 Steve, Here’s my revised analysis based on a start at Ft. Ward at about 9:45 and a 4 hour racer. This disagrees with yours a fair bit, except we’re both suggesting CW would be best if the predicted N wind sticks. Any other opinions? …Tom Overview This estimate is for Saturday September 12, with racers starting from Fort Ward. Without considering wind, CCW may be more favorable since racers will spend less time fighting the current in Rich Passage. CCW may also have a slight advantage with the current through Agate Passage. However winds are forecast to be out of the N, which would tip the balance towards CW direction. The 9-mile E side of the island is exposed and a downwind leg is preferred. Counter-Clockwise A 3kt ebb will push racers to a quick exit from Rich Passage. On the S and SE end of the island a weak ebb will be beneficial. By the time racers reach Agate Passage (11 miles from the start) at about 11:15 a.m., they will be aided by a weak but building flood of 1.5 to 2kt. The current will aid racers on the NW side of the island, and transition to hindering them on the SW side as the flood into Rich Passage takes effect. A 2kt flood tide will hinder the entrance into Rich Passage with it weakening to 1kt near Ft. Ward. Clockwise Racers will immediately face a 3kt ebb through Rich Passage, and will also be hindered around the SW side of the island. The W and NW should be mostly slack. The entrance into Agate Passage is about 15 miles from the start - it is slack at 10:47 and builds rapidly to flood. Early arrivals will see slack or a light flood, but later arrivals will face 1.5 by 11:30 a.m. A weak flood will aid racers on the E side of the island and back into Rich Passage. One strategy would be to work hard the first part of the race to get out of Rich Passage and through Agate early, then cruise downwind on the E side of the island. Tidal Currents Agate Passage N End - Flood Direction, 230 True, Ebb (-) Direction, 032 True Max Current -2 kt (ebb) at 7:44 a.m. Slack Water 10:45 a.m. Max Current +1.7 kt 2:03 p.m. Agate Passage S End - Flood Direction, 216 True, Ebb (-) Direction, 037 True Max Current -3.9 kt (ebb) at 7:56 a.m. Slack Water 10:48 p.m. Max Current 4.2 kt (flood) 2:10 p.m. Rich Passage W End - Flood Direction, 238 True. Ebb (-) Direction, 055 True Max Current -3.4 kt (ebb) at 9:05 a.m. Slack Water 11:29 a.m. Max Current +3.2 kt (flood) at 2:55 p.m. Rich Passage Off Pleasant Beach Max Current -3.1 kt (ebb) at 9:26 a.m. Slack Water 11:59 a.m. Max Current 1.7 kt (flood) at 2:48 p.m. Sources http://www.deepzoom.com/index.html https://tidesandcurrents.noaa.gov/currents15/tab2pc2.html#17 From: Steve Bennett [mailto:bennett_seattle@...] Sent: Wednesday, September 09, 2015 4:43 PM To: tkreyche@...; SoundRowers@... Subject: Re: [SoundRowers] Bainbridge Currents for Sept 12, 2015 So then, with the start now at Fort Ward, our hat is cocked; the tables turned. Here's my new read: Leaving Fort Ward, clockwise, within an hour of slack, a 5 hour racer should arrive at the Agate Pass Bridge with a favorable current of 2 kt, and slower paddlers will benefit even more. Had he opted for counter-clockwise he would be fighting 3.5 kt at the bridge. There'll likely be no contrarians this year. Also for your planning: · It is 15 miles from Fort Ward to the Agate Pass Bridge counterclockwise. · It is 11 miles from Fort Ward to the Agate Pass Bridge clockwise · Halfway is at about the middle of the big bay that extends from Agate Point to Point Monroe (which is just around the corner to the north from Fay Bainbridge) Any other thoughts ? Steve |
|
|
|
Tom Kreyche
Steve - yes, you are correct it's about 15 mi CCW to Agate from Ft. Ward...Tom From: "Steve Bennett" To: "tkreyche" , "SoundRowers" Sent: Thursday, September 10, 2015 9:03:31 AM Subject: Re: [SoundRowers] Bainbridge Currents for Sept 12, 2015 Tom, Nice work. I defer to your analysis. You have caught my error: I either foolishly or mistakenly equated the flood at Agate and Rich. Slack at Rich is over an hour later at noon. The tide is at ebb in Rich until then. I think the Counter-Clockwise distance to Agate Bridge from Fort Ward is 15 miles, however. Steve |
|
|