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Navigation, Weather & Instruments
FirstShift intelligence on offshore weather, routing, navigation, GRIBs, instruments, polars and race decision support.


The second greatest offshore race, The CYCC Sydney Hobart race - Discuss?
There is a boat I’ve owned that has already sailed the race I never have. The rebuilt S&S 34 Morning After, 56 years since her first Sydney Hobart race Morning After is an S&S 34, the sister of the Morning Cloud that Edward Heath took to Sydney in December 1969 and won outright. Morning After…

Stuart Greenfield
10 min read


From the Channel to Sicily: What to change for the Middle Sea Race, part 2
The strait of Messina - Chaotic, changing currents, ferries, gusts and who’s obeying the rule of the road… beware! Part 2: the Nitty Gritty bit…but first a story from closer to home: The anchor at Portland In 2016 I won my class in the Myth of Malham by stopping. Silver Shamrock , a Ron Holland…

Stuart Greenfield
12 min read


RORC Cherbourg race: Just 75 miles, how complicated can it possibly be?
There is a particular danger with the RORC Cherbourg Race and I don’t mean the shipping, the Channel tide or arriving at the French coast in the dark. It simply looks too easy. It is only about 75 miles from Cowes; start off the Royal Yacht Squadron, get yourself out of the Western Solent, cross…

Stuart Greenfield
19 min read


How to build a polar for the boat you actually sail
Many offshore crews are routing on numbers computed for a fictitious yacht. Here is where those numbers come from, why they go wrong, and how to replace them with your own.

Stuart Greenfield
23 min read


How did a 1968 boat with a handful of GRIBs lead the fleet for a week?
This weekend’s Round Britain and Ireland Race will be a great adventure, however, technology is unlikely to decide the winner... again!

Stuart Greenfield
8 min read


GPS spoofing and the return of real navigation
The modern offshore race boat is not short of screens. It may be short of independent truth, plus what Ukraine and Hormoz has taught us about technology

Stuart Greenfield
18 min read


Why TWA matters offshore -
Why true wind angle is the core offshore reference, and when apparent wind still matters and why I'm writing this update as questions have been asked.

Stuart Greenfield
7 min read


Should you stop trusting Lee Bow until you know which wind your instruments are showing?
The difference between feeling lifted, sailing fast, and actually making ground offshore, I try and explain it all.

Stuart Greenfield
12 min read


Offshore racing routing software in 2026
The tools are getting smarter. The navigator still has to be better.

Stuart Greenfield
17 min read


The ‘route’ of all evil or why grib files are barking mad
From charts and instinct to algorithms and GRIBs an offshore perspective

Stuart Greenfield
8 min read


How I set up race instruments for offshore racing (properly)
and why less is more and it works every time

Stuart Greenfield
19 min read
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