Some you have asked what gets a boat across the ocean successfully in this race, however you might want to define success. The really short answer is to learn french and go campaign a Figaro. It is the unparalleled trading ground for champion offshore shorthanded sailors. Ask Richomme or Sharp, two of the leading lights in this edition.
Short of that, you need skills and discipline acquired through other means. So here are my dirty dozen 1) Preparation - nothing finds your boat's weaknesses faster than 30+ knots of wind and slamming sea. Everything, and I mean everything on your boat should be tested and ready for that and in perfect running order. 2) Boat Design - In a box rule like the Class40, there are trade offs. Light is fast but fragile, wide and beamy is great on a reach but slow in light air. Your speed and success is going to be influenced by which design attributes are reflected in your life boat 3) Sails - a well built sail survives the abuse. A well designed sail gives you the 5% speed advantage 4) Navigation - this race has shown that these are lots of paths to Guadeloupe and some are better than others. Knowing the design of your boat and its speed potential under different conditions, getting good weather data and combining the two to make the fastest choices is key 5) Sailing Ability - knowing what sails to use, in which conditions, making those changes smoothly and cleanly, having good sail trim... all critical 6) Repairs - things break. Know how to fix them. Or improvise solutions. Sail repair, hardware repair, composites, electronics, engine mechanics. You need to be a jack of all trades. 7) Fitness - it takes physical fitness to change sails and move stacks of gear. Hit the gym. 8) Sleep Management - tired decisions are bad decisions. But over sleep and you hit things. Sleep management is a real thing. 9) Nutrition - you can be well rested and fit when you leave the sick, but with out a smart calorie plan along the way you will be weak and suffer from slow and sloppy execution 10) Anticipation - fix things when they look wrong, because when things get hectic that thing you left undone will either cause the issue or make it more difficult fo recover. And always look steps down the road and act early. Reef early and often. 11) Experience - If you have seen it and done it before, you can do it again. And better the second time. This is probably the best advantage a pro sailor has over amateurs- they just have the miles to know how to do it correctly and efficiently. 12) Luck