The stern squirt is one of the most classic things you can do in a kayak! Not only are its roots in the early days of freestyle, but being able to fly your stern under the water is a key component of slalom racing as well. Having a skill that is so well rounded is a must in every boaters quiver. The first thing we need is an appropriate boat. Some boats simply can not stern squirt based on what they were designed to do. For example a karma and a Zen are not the correct tool for this job due to the higher volume stern with a deck that is designed to shed water for creeking. A Fun, Fun Runner, or Rockstar are all great choices for this. They will all squirt a bit different so once you get your technique dialed try it in another boat, and keep an open mind that is willing to tweak things.
Now that we have our boat lets look for a nice defined eddy line. We do not need one that is crazy strong but rather well defined. Start in the eddy far enough back that you can get in just a few strokes that will let you get up to speed. This is not a sprint and we are not looking for max velocity, just nice even controlled forward momentum. This is important because timing is key and rushed sprints are hard to time. Approach the eddy line roughly at a 45-degree angle. This is not set in stone but a starting point. It will vary on each feature you squirt and the boat you are in. As your heels cross the eddy line you need to do something that you have trained your body not to do since the first day you started kayaking, lean upstream! This is a multidimensional move that requires us to balance our weight over the boat while letting the water do the work for us. By leaning upstream you are starting to present the stern deck to the main current. If left alone you would window shade for sure. In order to prevent this we need to provide an anchor point. The active blade on our paddle is just the anchor we are looking for. We want to wind our torso up as far as we can and plant the blade fully in the water on the downstream side of our boat. Try to get the paddle shaft parallel to the side of the boat for best results and a longer stroke. Now that we have our anchor set we want to focus on keeping our weight forward and lifting our downstream leg. This will drive the stern down and give the water more boat to work with. Also make sure you look in the direction of the spin. That little bit of extra torso rotation will help a ton. At this point the boat will start to spin as the bow rises out of the water, and you are looking at a well-executed stern squirt. Do not pull that blade out of the water until you feel the stern unload, or you will flip on to your face. Slow and long is the name of the game here. Do not rush it but continue to apply slow steady pressure on that blade by lifting your legs.
Now that you have the concept get out there and practice it as much as you can on both sides! Do not worry about getting the boat vertical right away. Gradually add more edge when you drop that upstream edge and work your way up. Once you can control the amount of lift the bow has try to bring it over the top and as you feel the stern unweight switch blades and roll up. This is a cool squirt boating move that you can do in a surface boat. Now that you own the stern squirt feel free to throw it into your river running bag of tricks to spice things up or to make a rapid change of direction mid line. Enjoy the process because learning new skills is the fun part.