Your first shot is always a good one to get -- the skier before things started. As you can see in the others, water skiing is a lot of work and skiers often forget to smile.
I haven't shot lately, but used to. When I did it was on film with unsophisticated metering and no AF.
Exposure
If the multi-segment meter in your camera gets the job done, go with it.
Less smart meters tended to have problems with white spray throwing off the metering.
To adjust for white spray, put the back of your hand towards the back of the boat, meter off the palm, open up one stop, then lock that exposure in. Recheck when you can or when the light changes.
At noon, light will be overhead, less flattering to the subject, but less changing. Overcast days will be the same, about 1 or 2 stops less light but steady light.
On bright sunny days your light will change a stop or two as the boat turns. The skier will be skiing into the sun, then away from the sun (backlit) or the sun will be on one side or the other. You may need to adjust exposure as the boat turns. The subject might not be identifiable in the backlit shots, but you can get pleasing shots, more abstract. Partly sunny with some clouds will give the sky something to do other than be plain blue, with exposures between full sunny and overcast when the sun hides.
When the skier is side lit, with film it was better to skip the shot and wait for better light, which might only be a few degrees left or right With digital, it's more easy to shoot extra frames then delete the image after the fact if it's not useable.
Shutter speed: You may be compensating for both subject and boat movement. Elbows into body seem to work better than elbows resting on thighs, which are attached to the boat and bounce with it. A monopod sits on the the bouncing boat and doesn't help.
Aperture: at 200mm, f5.6 was usually enough to get the skier and leave the background out of it.
Most of the time, the film speed was ISO 100-400. ISO 25/50/64 only on the brightest of of days and not best results.
Focusing/FL
The camera I tended to use didn't have AF, so MF and recheck was the only option. The rope keeps the skier roughly the same distance away, so once dialed in, radical focus changes weren't necessary.
Focal Length: I usually shot 200mm which would get the skier and enough of what was around them for context. 300mm for just the skier works, but is more of a portrait than an action shot.
Composition
This was the composition I found most to my taste after a lot of frames shot. Feel free to take it, use it or disagree with it and/or develop your own from pieces or none of it. There's more than one way to do this, this is just one.
Final comment: People tend to be appreciative of any photos taken. Memory trumps composition. So shoot the ones that aren't perfectly lined up too. If you get a better one, you can share those, but at least you'll have something to share.
Background Composition
It can be tough to pay attention to the background when paying attention to the skier, but try and keep the horizon line behind the skier level, when present. Skiers that throw up a wall of water, help this by covering over complex backgrounds. For those skiers that don't create a background for you, most bodies of water seem to have place where there are just trees and the background isn't complex, or there is a line of site where the background is far enough away based on where the boat is, and direction it's going into. On land, it can be possible to stand up and shoot down to handle the background, it's not a safe move in a boat. For tubers, kneeboards and kids, you'll shoot a little downward anyway and background may solve itself for those types of compositions
Like exposure, if you work the same body of water a lot, the best place to shoot for a good background or change a stop up or down will start to become second nature.
Composition of the rope and the skier and direction.
Skier
Putting the skier about 1/3rd of the way in from right of the frame, the when they are moving left, gives some 'frame' for the skier to 'ski' into. It's more dynamic then skier dead center in the frame. 1/4th or even 1/5th can work too.
Rope
The rope creates a leading line from or to the skier and the eye will follow it.
When the rope is frame left of the skier, it will take the eye right to the skier. Your IMG_4327 is a good example of this.
I tend to prefer this composition and will try to compose or crop so the rope enters the frame at the lower left hand corner or left side.
In general, I don't find the mirrored composition to be as pleasing. When the rope is to the right of the skiier, the eye finds the skier first, then the rope takes it and dumps it outside the frame. Example: IMG_4325. To see the effect of rope left or rope right, take an image into an editor and mirror it around the vertical axis. While there, you can play with crop and judge the effects of what part of the frame the rope enters - side, corner, or bottom, and where the skier is in the frame, center, or offset.
[Skier] Direction
Starting from center of the wake of the boat, the skier first skis 'out' of the frame. They turn, then ski back towards the center of the frame. In IMG_4327 the skier is heading out of the frame. In IMG_4324 and IMG_4325, the skier and his ski are both going the same direction, almost at the boat. This composition works better. The skier is facing the camera and so is their ski -- everything thing is coming right at the viewer. You can't set this up, you wait for it. Since all skiers have their strong side and off side, it might take a while to get what you want.
Skier, Rope and Direction Composition combined
Rope enters frame left bottom corner to skier frame right; ski and skier both going in the same direction facing frame left to frame center, and everything is lined up. If they managed to get a wall of water up, the background is taken care of. This composition works both horizontally and vertically.
Camera safety
When in a boat made for skiing (Mastercraft, Ski Nautique) with a low covered bow, if the driver turns into a wave at low speed a gallon or two of water may come over the bow into the boat. Coming over the bow, it won't look like much. I lost one camera that way. This usually happens when the skier falls and the driver turns to go get them. Put people safety before gear, but know if and when you need to protect your gear.
IMG_4050
