*This is not recommended by the manufacturer so try this at your own risk. Practice on land first.
When I use my Phantom 4, besides practice, I Launch and land from a boat 90% of the time.
With waves and at uneven surface launching from a boat is not the easiest method to launch your drone. The hand launch method, though not recommended by the manufacture, to me has been the most optimal.
With a little practice I have gotten pretty good at this method.
Here I show you how to launch and land your phantom while on the water.
This is not for every body but it works great for me so far.