Catching the smaller, slower moving bumps to connect into the bigger, faster moving swells. Guy Pere used a great analogy: use an "onramp" to pick up the speed you need to merge onto the "freeway". Then, as you come off the faster moving swell, look for an "offramp", a smaller bump that will keep your speed up as you come off the back of a bigger swell, which can allow you to maintain the glide and look for another faster moving "freeway" to merge onto. Just like when you want to merge onto a freeway, you need to accelerate on the onramp to go fast enough to merge into the faster moving traffic. On our Hawaii Kai downwind runs, the offshore winds create slower moving, shorter fetch, close period bumps that move to the left- the onramps. Longer period windswells and open ocean swells move more to the right and move too fast to catch without building momentum of the onramps. It's hard to get long rides on the freeways but the speed from those faster moving bumps are the reason why the fastest guys move so much faster on downwinders.