UPDATED Thelonious II Noon Position Reports, 2021


Sustaining Member
Bon voyage, Christian! I just found out this AM while having coffee and catching up on YouTube that you left for yet another solo to Hawaii. You are an inspiration to sailors who have reached 70, and beyond, that age is not that big of hurtle to accomplishing something with challenges as some people might think. Fair winds and a following sea to you!


Advanced Beginner
Blogs Author
No breadcrumbs.... :(

On the other hand, it's impressive to see that Marine Traffic was able to pick up a position update from AIS until he was ~240 miles out (1300 UTC on 3-July). Not sure what kind of magic was involved, that's a long way for a VHF-based signal to travel.

2021-07-03 thelonious.JPG


Junior Member
If you register at Marine Traffic (no cost) and put Thelonious in your fleet, you can get a noon updates by email. I don't know how they are doing this. I thought he had class B AIS. Maybe he is uploading these somehow? Today's given position is 769 nautical miles from Marina Del Rey. Here is the email from Marine Traffic:


Previous days:

July 1 departure time:

Time: 2021-07-01 18:21 UTC (11:21AM local time)
Position: N 33° 57.14', W 118° 27.60'
Speed/Course: 3.8 knots / 196°

No email updates from July 2 or 3 (but the above posts show his track for those days)

July 4:

Local Time: 2021-07-04 10:57 (Time Zone UTC-8)
Time UTC: 2021-07-04 18:57
Position: N 29° 40.02', W 124° 38.59'
Speed/Course: 6.3 knots / 235°

July 5:

Local Time: 2021-07-05 11:44 (Time Zone UTC-8)
Time UTC: 2021-07-05 19:44
Position: N 28° 59.56', W 126° 56.86'
Speed/Course: 4.5 knots / 268°

July 6:

Local Time: 2021-07-06 11:19 (Time Zone UTC-9)
Time UTC: 2021-07-06 20:19
Position: N 28° 18.73', W 129° 18.22'
Speed/Course: 5.7 knots / 257°
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Curator of Broken Parts
Blogs Author
MarineTraffic does report AIS data received by Satellites, but the last data field seems to suggest a terrestrial AIS data center as the signal source. Usually a specific shore station would be listed. Could be relayed from a weather buoy or something.

It's possible odd transient radio transmission paths can open up and a big shore station might pick them up sporadically. But I've seen too many ships listed on my AIS feed from 200 or 300 miles (and a couple of mountain ranges) away to believe that I'm getting a direct signal. (These show up using a terminal program hooked directly to the AIS unit, but they don't show up on connected devices like chart plotters.).


Junior Member
There is such a thing as a roaming AIS station. That is a ship that has agreed to upload AIS information similar to the way the land stations do. I saw some pleasure boats in the Sea of Cortez that said the AIS station was a cruise ship (docked nearby). Unless Mr. Williams has satellite AIS, perhaps he gets close enough to some ships for them to pick up his signal. Marine Traffic also has an app called OnCourse that lets users upload a position via satellite, etc.
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Dave G.

1984 E30+ Ludington, MI
I believe he has a satellite phone on board so maybe he can transmit position info that way ?


Junior Member
I did a little more reading about AIS. The satellite will pick up a class B AIS, but because the signal is fairly weak, it may not be picked up on every pass of the satellite. Also, Marine Traffic (free version) does not provide free tracking for these satellite fixes. Their paid service is $15 per month billed annually and for only one vessel (and you can't change vessels). However, I am receiving one fix daily from their free service. That's good enough for now. You can see pleasure vessels as pink on the Marine Traffic map. They are not individually named, but tomorrow when I receive the fix, I will see if there is a little pink vessel nearby that might be Thelonious II.

I just extrapolated based on the last two noontime fixes (current time about midnight PDT) and there's a little pink boat sailing westward! (You can read the coordinates in the upper right hand corner. Also you can see the distance scale at lower left for perspective.) Could it be the Thelonious II?

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Junior Member
I didn't get a position email today from Marine Traffic. :confused:

However, the Marine Traffic phone app lets you see satellite positions for 99 cents a day. His position is updated every 5 to 10 minutes. This is from a few minutes ago:


His speed varies. I just refreshed and he was going 3.3 knots at 230 degrees. The app says the winds are 11 knots, at 53 degrees, with a temperature of 68.
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Junior Member
Just based on mileage he is 39.9% of the way there (887 of 2224 nautical miles) to Ko Olina. Calculating hours using a constant speed (174 hours so far) he would arrive in 11.0 days. That's leaving out the variations in the weather of course. What say the experienced sailors?


"don't tread on me" member XVXIIIII
No breadcrumbs.... :(

On the other hand, it's impressive to see that Marine Traffic was able to pick up a position update from AIS until he was ~240 miles out (1300 UTC on 3-July). Not sure what kind of magic was involved, that's a long way for a VHF-based signal to travel.

View attachment 39547
yes it is +++


Junior Member
I received a noon position email today. The app says the winds in his area are 13 knots at 46 degrees, temperature still 68.
This is 88 miles from yesterday's position, but that reading was taken almost 3 hours late, it would have been about 100 miles for the full 24 hours. The average speed for the day was 4.2 knots. He is 964 nautical miles from Marina Del Rey with 1260 to go. He should reach the halfway point in a day and a half.

Everyone can follow Thelonious II on Marine Traffic. Open the map and move your mouse so that the coordinates at the upper right of the screen match the coordinates I have below. He is the pink "pleasure craft" heading WSW.

Here is today's breadcrumb: