The act of water meditation first requires to believe in the cleansing power of water. Then, you say a silent prayer to water to relieve you from your sufferings whatever it may be.
A tub of water may be mixed with an aromatic oil. (No don't call it yet as aromatherapy). A few drops of pure sandalwood oil is ideal. After saying your prayer, get into the water tub and relax for about 15 minutes. While inside the water, do some basic breathing exercise.
Don't focus on your sufferings that you have already prayed for. Focus on your breathing only.
Finally, after you get out of the tub say a silent thanks to the water for making you alright. It is important.
My husband used to do this in a swimming pool by letting out of the air in his body, sink to the bottom of the pool and lay there for just 120 seconds.
That was 30 years before. Now, he won't even step into a water tub.
Another form of water meditation is to just listen to the sound of water falling from a fountain or the sound of flowing water in a stream. This should be a daily meditation for 15 minutes. It has done wonders in my life.
Here, listen to the sound of running water.