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Optimum OS3 Timer

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The Optimum OS3 Timer is a large faced watch designed specifically for the needs of the active sailor. The massive 16mm digital number height makes reading numbers simple as possible. Handy countdown features (specific to sailing starts), a sync button and water resistant/shock resistant construction make this watch a great choice. Wear it on your arm, on your sleeve, or mount it on the boom or mast with supplied bracket.

  • Large 65mm overall ABS case
  • 38mm x 20mm display size
  • Massive 16mm digit height
  • Single row display
  • Adjustable Viewing Angle
  • Boom/Mast Mount Bracket Supplied
  • Elasticated Strap for Wrist or over sleeve wearing
  • Water Resistant to 5 ATM
  • Shock Resistant Construction
  • Normal Timekeeping Mode (12 or 24 Hour)
  • Specialist Sailing Timer Functions
  • Countdown repeat option
  • Countdown and Up to show elapsed time for handicap races
  • 5,4,1,0 ISAF start sequence pre-programmed with audible warning signals (can be silenced if preferred)
  • 5 minute, 3 minute and multiples of 1 minute programs as well
  • "Sync Button" for instant synchronisation if a gun is missed

Instruction Manual (PDF Link)

Reviews (3 reviews) Hide Reviews Show Reviews

  • 5
    Better than the new Ronstan

    I had a Ronstan Clear Start that died of old age. Bought a new Ronstan that was a disappointment in two ways. Did not have a 3-minute countdown option, and would not lie flat on a life jacket. This new Optimum is like the old Ronstan, meaning much better than the new Ronstan.

    - Bill Conerly

  • 5
    good, reliable watch

    These look the same as the old Ronstan watches, but for some reason these are much more durable. I found the Ronstan eventually leaked and failed, bit I have never had a problem with these Optimum watches, except that my kids keep losing them.

    - Jeff

  • 5
    A workhorse watch that is easy to use!

    Formally known as the big blue Ronstan watch, this thing is a work horse. My last one lasted 6+ years until the battery finally died. I've since replaced it with the yellow Optimum version and still can't complain. Easy to use and navigate, chimes are easy to hear, display is easy to read and sync button is easy to find in a panic. I recommend putting on the shoulder strap of your life jacket or mounting to boom/mast as, due to it's size, it does tend to get caught in rigging at inopportune times.
    Reviewed by Kyle Eaton, West Coast Sailing Inventory Manager.

    - Staff Review