Wreck of the PB4Y Privateer resting in Lake Washington


PB4Y Privateer resting in Lake Washington from Ben Griner on Vimeo.

Today was yet another great dive on this amazing wreck. Our goal today was to document the cockpit glass and two side turrets for comparison to previous video. This plane rests in 154' freshwater just off sandpoint.

For full HD click the video title and watch this video on vimeo.

Video Survey Dive of the PB4Y Privateer in Lake Washington

Today our team dove on the wreck of the PB4Y Privateer resting in 150’ in Lake Washington. Scott Christopher and Geof Corriveau dove locating the plane and tying in. Upon finding the wreck they shot a small surface marker and Ben Griner and Greg Wilson dropped on the wreck behind them.

PB4YCockpitGlass.gifEach team spent twenty minutes on the plane followed by a 50% O2 decompression. Both teams used Ratio Decompression calculations independently calculating their own deco schedules based on actual average depths and run times. Viability on this dive was approximately 7-10’ and surface conditions were sunny and calm. In all it was a great day to be on the water. Marc Greenway and Shaun Gardner had the duty of captain and surface support today.

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Outside and inside cockpit

This plane is in excellent condition despite failed recovery attempts by the navy following it being ditched. Four of its anti-aircraft guns are still in place and three of the four engines remain.

Side scan imagery of the PB4Y Privateer in Lake Washington

Below is an image of the PB4Y Privateer resting in 154 feet freshwater in Lake Washington. This plane is notoriously hard to get a strong or clean image on side scan. In this image you can see the planes profile with enough detail to see the step up for the cockpit as well as the shadow of the planes elevated wing. The bump you see on the planes top over the wing is actually a reflection of an engine housing on the far wing.

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The side scan actually picked up the hand reel we left hanging on the drop line following a recent dive here.  We try to place our drop line in this general location on every dive as the planes wings do not show on the depth sounder.  This placement ensures we protect the sensitive wings from the lead shot.

 

 

 

The second image is looking down on the plane. Again due to the planes poor sonar signal the edge detail is not strong but the plane is clearly detailed.

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PB4Y downhill scan in Lake Washington showing a two large boulders west of the plane.

If you take a look at this sidescan image of the PB4Y you will see two large signatures off the nose of the plane. These are the infamous boulders that are occasionally dropped on by mistake. You can see that due to their size and close proximity to the plane that they could easily be mistaken on a depth sounder for the plane which typically has a poor signal due to its positioning.

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With this said, divers who are familiar with this site are able to swim from the rocks down to the plane.

PB4Y uphill scan in Lake Washington showing the hillside topography.

This scan was taken much like that of the 520 vessel #2 image. The side scan unit was placed very close to the bottom and turned up to allow the capture of as much of the hillside as possible. This image shows the shelf contour as it drops from 80’ to 200’.

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For those of you who enjoy scootering this wreck from shore these images should give you a good idea of your navigation. Our team often scooters this wreck as the shelf allows for a comfortable and natural decompression. We are using a 70’ single 50% bottle for this dive and ratio deco with our clock starting at 80’. This profile gives plenty of time on the wreck.

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If you have not been to this wreck by scooter please note that this plane is nearly a half mile from shore and there are gentle cross currents in this area.  Should you be forced to do an open water deco you will certainly be a long way from where you want to be. Measure your burn times ensuring your buddy can tow you home (or at least up the hill to deco). Attempting a swim from the plan back to the 70’ mark will extend your bottom time beyond the capacity of your 50% bottle.

On-going exploration of the PB4Y by PugetSound Divers

Over the course of 2007 PugetSound Divers recorded more than 14 hours of bottom time on this plane. This is one of the more fun wrecks in Lake Washington and sitting at 145’ deep it is rather easily accessible.

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Click here for more information about the PB4Y and this picture.

As with all the sensitive wrecks in the lake there is no need to anchor and further more we ask that all dives to this site use a light drop line and drop at least 50’ from the plane. Because the wings do not give a good signal on the depth sounder our team drops in on the tail placing the drop line in 160’ and swimming up the slight grade to the plane. This positioning will ensure that you do not accidently drop your shot directly on the wreck.

We will post video of this site soon.