Environmental Projects - Olympic Coast National Marine Sanctuary

Dungeness Spit, Sequim, WA

Olympic Coast National Marine Sanctuary

Snohomish Estuary, Tulalip Tribes, Everett, WA

Olympic Coast National Marine Sanctuary

Global Remote Sensing, LLC was contracted to survey areas within the Olympic Coast National Marine Sanctuary (OCNMS) for the sunken fishing vessel Ocean Tor. The survey was conducted between November 1st and 5th, 2005. The survey vessel Kvichak Defender IV (Figure 1-1) was mobilized for all survey operations. GRS conducted a side-scan sonar survey to locate the Ocean Tor along the western boundary of OCNMS. The survey's orientation was north-south within an area designated with a high probability for finding the vessel (Figure 1-2), as determined by NOAA's Hazardous Materials Response Division.

The Ocean Tor, constructed in 1974, was 70 feet long (21 meters) and 90 gross tons. The FV Miss Leona recorded the Ocean Tor's last known position (48-05N, 125-22.1W) on July 27, 2005, at 2020 Pacific Daylight Time. The Ocean Tor was drifting SE at the time. The oil sheen associated with the vessel sinking was observed by a Coast Guard helicopter at 1500 and 1840 on July 28, 2005. It was assumed that the Ocean Tor was resting on the bottom below the western extents of the oil sheen.

Based upon GRS's experience in locating objects on a seafloor bottom using side-scan sonar, there was no indication that the Ocean Tor is located in the designated survey area. Despite the very high-resolution and detail in the imagery, the vessel's location remains undetermined, certain that the Ocean Tor was not resting within these bounds.  Examples of this imagery, Figure 1 and 2, show that a vessel of this size would have been easily recognized if it were to be within the survey area.

Originally it was feared that there was a possibility that the Ocean Tor could be buried under moving sand on the seafloor and therefore unable to be seen in the side-scan sonar records. After post survey review of the data, this is not believed to be the case. The sonar records show many well defined trawl marks rocky seabed features and anthropogenic debris throughout the survey area. These marks and targets demonstrate that there is little sediment movement or deposition that would be necessary to hide a vessel as large as the Ocean Tor.

(Images: Figure 1. 21 Meter Object Adjacent to Average Surface Debris.  Figure 1. Scour Marks and Debris From Segment of Line 310-2121.)