hmm

So, I ran the calculations for Vendee.

Total Distance Travelled

Globe = 45,000 miles
Flat Earth = 75,000 miles

In both cases, the round trip from Europe down to about 55 latitude South (which is where they go around ... globe/FE) would be about 15,000 miles.  So, the difference here is because at 55 degrees, the trip around the Globe would be 30,000 miles, while the trip around an FE would be 60,000 miles.  So that's the difference, about 30,000 miles

So, the record for completing this race is about 75 days (a shade under, but then the math is easier with round numbers).  I read an article explaining that with 24-hour auto-pilot and taking advantage of currents and winds that move around the Globe, the boats go full speed 24 hours per day and average 35MPH during the entire race (though they're capable of top speeds closer to 47MPH).  This technology (plus taking advantage of winds/currents) has brought the record down from 109 days to 75 days in more recent years.

OK, so let's do the math.

75,000 miles (FE) at 35MPH would require 89 days to complete.
45,000 miles (Globe) at 35MPH would only require 53 days to complete.

So why isn't the record closer to 53 days instead of 74-75?  I think that the mileage might be a little high because they do cut some corners, where they don't actually do the full circle around "Antarctica" (as you can see below).  So if you shave off some of that mileage due to the corner-cutting, and go above the average sustained speed of 35MPH, you're very close to the 75-day record.  On the other hand, given the 35MPH sustained speed, you should be able to complete this race on a Globe in 53 days.  These guys are pretty competitive, so you don't think someone could have gotten closer to the 53 days?

If the total distance is closer to 70,000 miles (due to corner-cutting, which on an FE map would result in significant savings) and their average speed goes up to 39MPH, that gives you the exact current record of about 74/75 days.

Meanwhile, at 45,000 Miles, they'd be only travelling an average of 24 MPH.

You're not supposed to turn left on a Flat Earth either. The whole concept of the Flat Earth is that if I travel straight in one direction, e.g. East, I will actually take a curved path as all lines of latitude curve around the North Pole in the centre.

I think you confusing cardinal directions with relative direction.