I can't tell you very much, because try as I might, I'm not real good at chop hopping and flat water jumps.
I spent an afternoon once, many years ago, with a guy who was very good at it.
Here's what I know.
It's all about timing.
You have to "lift off" at just the right time, when your board hits the ramp.
I couldn't get my board more than 6" off the water until Keith "gave me the secret".
We were in at the beach and he had been watching my miserable little "bounces".
So, he explained his "spring" concept to me and had me do a few "jumps" right there on the sandy beach. No board involved....!
If you stand erect, and flat footed on the beach, see how high you can jump....... try it several times.... not much height...right?
Now pretend you are a spring, crouch and coil your body and get up on the balls and toes of your feet.
Leap up as high as you can from this position...... much better, right, normally at least twice as high as when you stand flat footed.
OK, now lets take it all out "on the water".
When you want to "chop hop" you ned to sail along and get some good speed. Then "coil up" as much as you can like you did on the beach. Become a spring.
When you see a likely ramp (for me it always seems the better looking ramp is right behind a not so good looking ramp and getting over the first to get to the primo 2nd ramp makes the timing and control even more difficult).
When your board hits the ramp and starts up, "UNCOIL" like you did on the beach and you should see a little altitude.
Timing is the critical factor.
In order to "UNCOIL" you need to push down against something.
The trick is to time when you push down to "UNCOIL" or "SPRING" up off the water to coincide with the "pop" from the board going up the ramp.
Get it too early and you lose you speed and not much happens.
Get it too late and your board wants to "pop" up off the ramp, but you "absorb" all the energy with your legs because you didn't "spring" at the same time.
"Flat Water Jumps:
I'm really not good at these, but if you watch some of the free style sailors, it's really the same "porpoise" type motion that you might use to clear a fin, taken to a much higher degree.
Since there's no "ramp" to pop up off of, you need to "bounce" your board a little to get it to pop up a little on it's own.
It's very similar to very light wind pumping where you coordinate the bouncing with pumping motion (down and back quickly) of the rig to pop the board onto a plane.
Same thing here, you need to get the board "porpoise"-ing, and then
spring up and bring your rig back and almost to horizontal at just the right time.
Give it a try, and remember, in my opinion, the more you can become a "spring" the easier it will be.
There are some good video's on the Sailworks site of Phil Soltisiak and Dale Cook doing both free style (Phil) and huge jumps (Dale).
Take a look at these videos and you will begin to see how each of them uses the "spring effect" to accomplish some pretty incredible windsurfing feats.
Here's the link to Phil S in Brazil
There's a link to Dale Cook "blasting off" in the Gorge on the same page.
I just viewed these videos, and there's one more ""timing" thing to add in here.
When to really pull the sail back and down to get the max. altitude.
I'd work on getting the board up off the water first, and then work in getting the rig parallel ot the surface of the water for more "float".
Hope this helps,