Keystone Jetty

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carlk3
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Re: Keystone Jetty

Post by carlk3 » Thu May 16, 2019 8:00 pm

YellowEye wrote:Not sure if its 168'/2.

Probably about that, but if the water gets (for example) 4 feet deeper, the rocks have to go out another 5 feet!

We turned around when we saw an orange-painted concrete block on the sand in about 54 fsw. We don't know, however, if it was put there as a turn-around marker.

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ScubaJess
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Re: Keystone Jetty

Post by ScubaJess » Thu May 16, 2019 4:48 pm

Great info carlk3 , thanks for posting this :)
Live Long And Prosper!!!

Stay Warm underwater with the Weezle Extreme Plus undergarment! Please let me know if you would like to order one or have any questions. :luv: :partydance: :eric: :taco:

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YellowEye
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Re: Keystone Jetty

Post by YellowEye » Thu May 16, 2019 4:41 pm

Very cool! Its definitely not a square pyramid at the bottom though. The bottom shape is more of a horseshoe on an uneven bottom. So its easy to go around the jetty and not even realize it! It might be interesting to map how far you are out in the water column if you were to come straight up from the farthest out point... Its fairly far out! Not sure if its 168'/2.

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carlk3
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Re: Keystone Jetty

Post by carlk3 » Thu May 16, 2019 1:17 pm

Here is a new un-official crosssection of the Keystone Jetty at the deep end.

Image

Diving the Keystone Jetty last Sunday made me curious about the structure itself. I found an Army Corps of Engineers report(p155-6) and created the mash-up above.

From this we can calculate answers to questions like:

    Q: How much of the jetty is underwater on a +10 high tide?
    A: By area, at the deep end, 1% of the jetty sticks out and 99% is underwater.
    Q: What volume of the whole jetty is underwater on a +10 high tide?
    A: Via some assumptions and Excel-approximations, about 2.5% sticks out and 97.5% is underwater.
This all assumes the straight part of the jetty ends at 60 fsw on a +10 tide. Is that right?

I also wondered about the length of the jetty. An Alert Diver article gives the length as 75 yards. To my eye, that looks right
20190512_053724-Edit.jpg

but (measuring from around the high-tide mark) Google Earth says about 127 yards, so that's the figure I used.
GELowTideJetty.JPG


Finally, here are two items from the Army Corps of Engineers report. First, their official crosssection for about 30 fsw on a +10 high tide:
crosssection.JPG

and this dateline for the jetty's Construction and Rehabilitation:
  • 1945 The project was adopted.
  • 1947-1948 The project was constructed, including 28,000 tons of rock for a 1948 breakwater, and the basin and entrance channel were dredged.
  • 1950 The breakwater was repaired.
  • 1954 The breakwater was repaired with 700 tons of rock.
  • 1960 The breakwater was restored to design height and lengthened 175 ft, and an easterly spur was added for protection against southeasterly storms. The repair work required 871 tons of rock for the breakwater plus 505 tons of quarry spalls. An additional 6O6 tons of quarry rock were added to a revetment.
  • 1971 The entrance channel was widened to 200 ft to reduce the frequency of dredging.
  • 1985 The harbor and cross section of the breakwater are illustrated in Figure 72. No repairs or rehabilitation to the structure have been recorded since 1960.

We stayed overnight in Oak Harbor. Awoke at 4:20 AM and drove to the site (be careful of deer on the pre-dawn road). The dive books -- Fischnaller, Pratt-Johnson -- say to adjust the slack before flood by -31 minutes (PlanYourDive.com misses this). We dove the jetty for the first slack. Ate at the under-new-management resturant (recommended) and then dove the pilings on the second slack. We had great dives, with 30' vis.

- Carl
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mike77jm
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Re: Keystone Jetty

Post by mike77jm » Tue Mar 26, 2019 2:54 pm

Regarding the cafe, it appears to have reopened under new owners:
https://www.callensrestaurant.com

It's a little pricey, but the food and service was pretty good.

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Re: Keystone Jetty

Post by mike77jm » Wed Feb 06, 2019 2:40 pm

Thanks!

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60south
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Re: Keystone Jetty

Post by 60south » Wed Feb 06, 2019 12:34 pm

mike77jm wrote:

The above chart has changed from Admiralty Inlet to some place in New Jersey.



Thanks. Yeah, mobilegeographics keeps changing their site. Lately, the normal Point Hudson prediction brought up someplace in China... :tomnic:

Try this one:
http://tbone.biol.sc.edu/tide/tideshow. ... on+Current

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Re: Keystone Jetty

Post by mike77jm » Wed Feb 06, 2019 9:27 am


The above chart has changed from Admiralty Inlet to some place in New Jersey. I typically use Northwest Shore Dives (Fischnaller) as a reference; Fischnaller references Admiralty Head, but NOAA appears to have discontinued use of that station. At this point, the closest current prediction station I can find from NOAA is Marrowstone Point, 1.65 mi NE of. If I apply Fischnaller's -31min SbF and +1min SbE to the prediction 1.65mi NE of Marrowstone, I get a prediction that roughly lines up with what planyourdive.com gives me for Keystone. The couple of times I've been to Keystone recently, planyourdive.com seemed to be fairly accurate, but I have been warned not to trust its predictions.

For those of you familiar with Keystone, which current prediction station do you use, and what adjustments do you apply?

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60south
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Re: Keystone Jetty

Post by 60south » Wed Jan 17, 2018 9:00 am

YellowEye wrote:Note: the café across the street is now closed and out of business. Hit Pickles, Greenbank Farms pie shop, or one of several shops in Coupeville instead...


Site description updated, thanks.

ScubaJess wrote:Someone needs to buy the old keystone cafe and turn it into a 1/2 dive shop & 1/2 coffee & dive bar!!! :-)


Absolutely! Um, anybody care to loan me $700,000?

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ScubaJess
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Re: Keystone Jetty

Post by ScubaJess » Wed Jan 17, 2018 8:10 am

Someone needs to buy the old keystone cafe and turn it into a 1/2 dive shop & 1/2 coffee & dive bar!!! :-)
Live Long And Prosper!!!

Stay Warm underwater with the Weezle Extreme Plus undergarment! Please let me know if you would like to order one or have any questions. :luv: :partydance: :eric: :taco:

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YellowEye
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Re: Keystone Jetty

Post by YellowEye » Tue Jan 16, 2018 9:29 pm

60south wrote:Nearby Facilities: Washrooms and a shower on site. A cafe across the street. The nearest dive shops are in Oak Harbor and Port Townsend.



Note: the café across the street is now closed and out of business. Hit Pickles, Greenbank Farms pie shop, or one of several shops in Coupeville instead...

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60south
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Re: Keystone Jetty

Post by 60south » Tue Jan 16, 2018 8:24 am

We did a "drift" from the pilings to the jetty yesterday. I put drift in quotes because the current was so light it was actually a swim. And it's a looong swim if you aren't being helped along.

Also, the thick rope that leads from the pilings ends about 2/3 of the way. There is a large anchor (~45fsw) and then... pfft. No more rope. If you continue to follow a contour at, say 45ft, you'll eventually hit the jetty.
Last edited by 60south on Tue Apr 24, 2018 4:20 pm, edited 1 time in total.

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jmartel
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Re: Keystone Jetty

Post by jmartel » Sun Aug 06, 2017 9:27 pm

60south wrote: It's possible to drift from the warf to the jetty in a single dive, sometimes helped by a push from the current.


In my experience, drifting from the wharf to the jetty is unavoidable. Even more fun off slack. :rofl:

Should probably put a note in that there's a thick line around 45ft FSW from the wharf to the jetty. Drops you off right at the middle of the jetty. No need to worry about if you will get blown past if you follow that.

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60south
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Keystone Jetty

Post by 60south » Sun Aug 06, 2017 12:29 pm

Dive Site Name: Keystone Jetty

Skill Level: All Divers, with caution

Current Sensitive: Yes. Use current tables for Admiralty Head: http://tbone.biol.sc.edu/tide/tideshow. ... on+Current

Location/Address: Fort Casey State Park, Whidbey Island, WA

Directions: Driving from Seattle, take the Mukilteo Ferry to Whidbey Island. Drive 22 miles north on Highway 525, turn left to the Port Townsend Ferry and Fort Casey State Park, and drive 3.5 miles to Keystone. From Port Townsend, simply take the ferry to Whidbey Island and you're there.

Free Parking: Discovery Pass Required. $10/day or $30/year, as of 2017

Staging Area: Good -- Parking is near the water, with picnic tables for staging.

Surface Swim: Short.

Nearby Facilities: Washrooms and a shower on site. The nearest dive shops are in Oak Harbor Anacortes and Port Townsend.

Special Considerations: No underwater hunting or fishing in the conservation area.

Maximum Depth: 60ft, although much of the life is shallower.

Known Hazards: Strong currents are frequent here, and the ferry arrives on the other side of the jetty. Do not go 'around the corner' into the ferry lane!

Dive Site Description: Dive along the east side of the spit and find a seemingly endless variety of life in the rocks. Wolf eels, octopus, nudibranchs, ling cod, rock fish, and many other species are commonly seen here. Be careful as you approach the end of the spit because the currents may be rippin', even during a supposed slack tide. Up the beach is an abandoned warf. It's shallower but also shelters an amazing array of critters. It's possible to drift from the warf to the jetty in a single dive, sometimes helped by a push from the current. There's a rope at ~45fsw that runs from the warf to the about the middle of the jetty, follow that. Keystone Jetty is indeed a crown jewel of Northwest diving.

Check out Brandon Cole's excellent article in Alert Diver.

keystone.png
Last edited by 60south on Thu Feb 07, 2019 7:29 am, edited 8 times in total.

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