An article on the technical aspects of the search for Tenacious appears in the recent yuneec-q500-4k features July 2011 issue of Communications of the ACM. Below is a note I wrote to some of the people involved — if it should have gone to you too, my apologies. And please go ahead and add your insights to the comments at the cacm website.

Hi everyone:
It’s been a very long time since I’ve written this group. But after years of pauses, delays and editing, the (shortened) article on our efforts to find Jim and Tenacious appears in this month’s Communications of the ACM.

I don’t think of this as an article that David and I wrote, more something that we wrote down, on behalf of us all. In the article I wanted to maintain the group spirit, and I had to deal with my spotty knowledge about the full effort. I don’t think any of us had the full picture, or ever will. So I explicitly avoided calling out individual volunteers by name. I would have made painful mistakes and imbalances had I tried to get that right. My apologies to you all for not capturing your contributions as accurately as they deserved. And for not including all the relevant people on even this email — please do forward along to your colleagues.

I also want to apologize for the delays getting this out. It shouldn’t have taken even half this long. And it should have come out far more clearly and simply. But there — it’s out now, and others will hopefully get some technical insight from the ingenuity and heart we all put into this, despite the delays and the writing.

I want to encourage you all to add your corrections and perspective to the article, either in the comment box at the end of the CACM link above, or in your own blogs or other online venues.

Best wishes to all.

All are invited to the Tribute to Jim Gray, May 31 2008, at UC Berkeley. Although Jim will be listed as missing until 2011, his wife Donna Carnes has asked that we have this Tribute now, to honor him, before too much time has passed. There are two parts to this event: the morning event, which will be in a very large hall, is open and public; the technical session, which is in a smaller hall, we are asking people to register for (on the web site), so we have an idea of how many are coming.

Please go to the tribute website for information, and to register.

– Joe

It has been many months of quiet here.

However, there is a new, very well-done article by Steve Silberman in Wired this week that was done with input from the family, the Coast Guard, and many of Jim’s friends and colleagues. The article describes the efforts made by so many — including folks active here — to help find Jim. I recommend it.

Anyone with information about Tenacious or Jim Gray should contact:

  • The San Francisco Police Department at (415) 553-1071.
  • The US Coast Guard at (415) 399-3547.
  • Our search email address,

Jim was last seen on January 28, 2007. Here are several photographs of him and of his 40-foot C&C sailboat, Tenacious, sail number 31869.

Since January 28, the San Francisco police, the Coast Guard and Jim’s friends and family have conducted an extensive search to find him and his sailboat, Tenacious, off the California coast. I want to summarize the status of that search here, so that the broad volunteer community that’s done so much knows where we stand.

The Coast Guard’s air and surface search covered 132,000 square miles in the days immediately following Jim’s disappearance. This search was thorough: Planes, boats and helicopters covered much of the region repeatedly. Radio broadcast alerts were made for a week, and all marinas and harbors were canvassed repeatedly. It found no trace of Tenacious or Jim.

During the Coast Guard search and in the days that followed it, Jim’s friends and family assembled satellite imagery, collected wind and current data and arranged for more air and surface searches over the ocean and coast from Oregon and into Mexico. We have walked stretches of coastline and have postered marinas with details on the missing boat. The story has drawn attention from around the world.

Based on our knowledge of the boat and weather conditions, we do not believe that Tenacious could have outsailed our search, whether it was under power, adrift, sailing under autopilot, or even sailing at best possible speed. We have covered an enormous area.

In the last several days, the Friends of Jim group has reviewed all the data with Coast Guard officials. The fact is that we have no evidence as to what has happened to Tenacious or to Jim Gray. Neither we nor the Coast Guard can come up with a surface search plan that is likely to find either Tenacious or Jim, given everything that has been done already.

Accordingly, the Friends of Jim group is suspending its active effort to find Tenacious that has been centered here at the blog. For both the Coast Guard and the Friends of Jim, “suspension” means that the active search has been discontinued due to exhausting all present leads and the lack of new information. Of course, should we or the Coast Guard receive any new information, we will investigate it.

Understandably, Jim’s family is determined to continue to seek answers, but they deserve to be able to pursue them privately. The family deeply appreciates everything the Coast Guard and Friends of Jim have done.

Jim’s wife Donna asked me to add this statement of thanks from her on behalf of the family:

On behalf of our entire family, I would like to thank every individual and organization who helped, and is continuing to help, in a long and difficult search. As the search takes on a new direction, I want you to know that your faith, hard work and boundless creativity sustain us during this unbearable time.

Jim is very lucky to have you as friends and colleagues, and we are very lucky and grateful to have your support.

Below, in the previous post to the blog, we have posted recent photos of Jim, photos of Tenacious at anchor and under sail, and an email address where you can send any information that could help us with our search. Coast Guard and San Francisco Police contact numbers are also listed.

  • The e-mail address is
  • The Coast Guard contact number is (415) 399-3547.
  • The San Francisco police department contact number is (415) 553-1071.

Thank you, one and all, for this amazing effort to find our Jim.

Using ocean current models provided by the OurOcean group at JPL, we created an animated GIF, which shows where objects starting near the Farallons on the afternoon Jim disappeared would drift over the next 13 days. Relevant satellite and aerial imagery were obtained 2.6, 4.8, 5.1, and 5.8 days after the adopted zero point in time (Jan 29, 00:00 GMT). We are now reanalyzing the imagery that covers the convergence zones in the current models.

The JHU group

Note: In addition to the movie, we have added the data as suggested by Igor Carron

Just wanted to provide a quick update on our postering
efforts over the past few days.

We got additional poster coverage at some of the big
marinas in San Diego and Los Angeles; some coverage at a Seattle
marina; and also in various places across Mexico. People that we
run into in SoCal seem to have heard about
JG by one channel or another — our phone calls, reading the
news/web, or seeing it on TV. For those who are still putting up
posters or wanting to, please do get in contact with me through I am still routing people to areas
that are under-covered.

Thanks are due to Tim Takata, Arun Jagatheesan, Minna Ha and Mike
Blaszczak for helping with posters and Gurrola Alberto for
helping us coordinate in Mexico.

As usual, one can see what we’re doing at:

The storm that’s kept us on the ground for the last several days finally passed through overnight, so we were able to put two planes in the air today.

Those flights were aimed at specific search areas, based on results from our image processing and the work of our ocean surface drift modelling team. We had found two possible sightings of Tenacious in the imagery, and went out to look for it.

The first possible sighting was off the coast of Monterey, California. This image was captured by a NASA ER-2 overflight. The target was found by our image analysis team. We sent a flight out this morning that flew a search pattern over the area into which that boat would have drifted.

The second possible sighting was out past the Farallon islands, Jim’s intended destination on Sunday two weeks ago. This target was spotted by the volunteers working on the Amazon Mechanical Turk search, and was vetted by image processing experts who confirmed that it was the right size and shape to be Jim’s boat. As for the Monterey target, we put a plane in the air and flew a search pattern over the area into which we would have expected the boat to drift since the image was captured.

Neither of our flights found Tenacious. It was an excellent day for spotting, and we were able to see other craft and even wildlife — large submerged whales and orcas or dolphins at the surface.

We’re confident that the imagery shows sailboats, and that those boats are similar to Tenacious in size and shape. We flew thorough and careful searches. It’s highly likely that these were ordinary boats on the water, and in no distress. They weren’t Tenacious.

It’s good to see the results of our image processing and drift modelling turn up targets for our flight team. We still have imagery in the pipeline, and will put planes in the air as our analysis turns up new targets. Today’s results are disappointing, of course, but the search is still underway.

Thanks to those of you who got the science done, who arranged for the search flights, and who piloted or spotted on today’s flights.

We have updated with a list of possible targets from the RADARSAT images taken January 31st and February 3rd.  RADARSAT images are 12.5 m per pixel, so the boat should be about 1 pixel. Maybe not the best images, but we thought it was worth a try.

Maria Nieto-Santisteban & Jeff Valenti