The Florida locks sometimes raise and lower the water by opening the lock gates. Locking is usually a couple of feet or less. Regardless, the boat moves around quite a bit so man the lines and fenders. Never a floating bollard so never tie off the lines.One thing I completely forgot to mention above is where to position you boat in a lock if you have your choice of where to go. This info below is ONLY applicable when you are going UP in a lock because there will be currents inside the lock as it fills.
Now picture this: Let's say you are the only boat in the lock so no problem picking where you want. If you go all the way to the far end of the lock, when they start to fill it that water comes in near the center of the lock and will push against the stern of your boat. That push on the stern will make your bow move toward the lock wall, making control of your boat more difficult.
If you take the first bollard when you enter, as the water enters the lock and moves toward the ends, it will push against the bow of the boat. In doing so, it doesn't cause the "push" against the boat as it does when pushing on the stern.