They're catching some nice crappie now in the deeper water on the Lower Blue Basin. If you're going the last week in March, the crappie should be moving towards the shallow water or will already be there. But it depends on the weather and water temps. They've had a pretty mild winter so the water hasn't cooled down very much.
I always go the 2nd or 3rd week of April and they are usually spawning or close to it. If you look for boats all bunched up in a certain location such as Green Island Point that will tell you the fish are biting there. That is the deepest water on the lake. Swan Basin is just around the corner from Green Island and has water ranging from 3-10 ft deep.
If the crappie are in shallow, you can try Bell's Stumps (4-8 ft), If they are already in the trees spawning, Kirby's Pocket, Eagle Nest Timber and Buzzards Slough are good places to try.
The locals spider rig and slow troll over the stumps. If you can get a day where the wind is 3-4 mph it's just as easy to drift sideways with the wind and drag jigs and minnows at different levels. When you start catching fish, mark the area, and keep drifting over the area. I take a trolling motor and depth finder with me when we go. Have had good luck on red/char, black/char and blue/white tubes or bubblegum/char, orange/char or all charetuse curly tail grubs.
If it is windy, and it will be (always is) you can try fishing the lily pads in close to the bank or in the canals for bluegill out of the wind. That lake gets very dangerous when the wind blows so use your head about your safety. I have spent a couple days on my trips several times sitting on the bank watching the waves crash onshore. You'll be fishing in a 12 ft jon boat with a 6 hp motor and that's not a good match against a 15-20 wind.
Good luck and I hope this helps you some. I'll be there the 3rd week of April this year so don't catch all the big ones.