I use to live near Santee and fished it regular. The picture on my signature is from there. I am sure most fish have already spawned. However, don't be surprised if there are some scattered fish still on the beds. After the spawn you should find fish on the cypress tree. On lake Marion there is a major creek called Eutaw Creek. There is a landing near the main lake. Across the lake (cross the creek channel) there is a stand of cypress that is near deep water. You should check those out. One of my best bass in May came from those tree. Trick worms and senkos fished as close to the tree as you can get. There is plenty of deep water near the head with lots of boat docks. Across from the docks down the creek within site of the landing there is a submerged rock pile 40 yard off the bank. I don't think its on a map.
On Lake Moultrie there are a number of place to put in near Cross SC. Lots of backwaters. Blacks Camp has a good man made boat lane with grass right at the edge. FROG fishin at it finest but only if you get to it before a lot of boat traffic. In the canal you have several cuts that lead into deep water. Be aware, when they are pulling water the current in the canal is really fast.
Near Cross there is landing called Duck Pond. If you paddle out and turn to your right, it a long paddle or pedal all the way to the corner there is a backwater pond called Duck Pond. Excellent area!
Baits of choice are: spinner baits, senkos, trick worms, and Pop R's as long as it cloudy. Texas rig worms works 11" or bigger. I used to have a lot of luck on Zoom ole monsters in Scumpernong.
The lake can get bad quick. If you get a little wind it gets worse than Kentucky or Barkley. Be careful, lots of gators as big as your kayak.