What I now know is that Timex also produced a (maybe even rarer) surfing version, and that is what I'm wearing today.
It is called the Timex K-28 Surf, and is nearly identical to the Skiathlom. The Skiathlom watches seem to have come out in 1987 based on some info I found on a forum, but the K-28 Surf trademark request wasn't filed until 1988, so I guess this came out in 1988 or 1989 (when the trademark was granted). The watch is sometimes it is referred to as Chill Factor as this is written along the top of the watch. It is 50m water resistant, but because of the surfing theme, it calls it "50 meters wipeout resistant".
The watch has a 2 line LCD display showing day, month, and date (top line ) and time (6-digits, bottom line). It also has chronograph, timer, and alarm functions.
As with the Skiathlom, the watch has a temperature sensor, with the temperature shown in a bar along the top of the LCD display. Pressing the top front button also shows the temperature in numbers (Celsius or Fahrenheit).
With this watch there was also an attachment for the strap called Zebug. This is a small orange plastic container shaped like a beetle (with the name Zebug on the back). This was included as a place to store your sunscreen or lipbalm while in the water.
It uses the same back panel as the Skiathlom (even saying Timex Skiathlom). There is also the number 70 along with the battery type (CR2016) etched on the back.
For more on the Timex Skiathlom, see my page here