Before i start to detail the freefalling technique per se, i wanna give you a general view of the dive. When you dive, around the first 10 meters, you have positive buoyancy. It means that you need to kick or you need to pull the line, depending on the discipline you are practicing, to keep going down.You need to use some power. If you are kicking, you need to have some amplitude in the kick, you need to put some energy to fight against the buoyancy. The buoyancy is pushing you to the surface and you are counter buoyant, you are going deeper. In the first 10 meters there is positive buoyancy, so you need to kick with power and amplitude.
Then there is a middle depth, that can be around the 10-15 meters, in this range, where you are neutral or almost neutral. It means that if you stop moving, you stay almost still, almost no movement for a moment. In that part of the dive, you should keep kicking, but you don't need to use a lot of power in the kick, you can relax a little bit the energy and the position you take with the kick. So, the amplitude of the of the kick don't need to be super big and you can relax a little bit more. And finally after 15-20 meters, depending on the depth you are going, you can stop kicking and this is the freefalling. You freefall in the last part of the dive.
Timing
To be able to freefall correctly and efficiently, one of the things you need to understand is the timing - when you should stop kicking, to take advantage, to start flying into the depth. Normally, in average, when you are intermediate level freediver, then you are freediving around the 30 meters, 40 maybe 50 meters, you should have the neutral buoyancy between 10 and 15 meters approximately. That means that you should start your freefall after 15 meters. If you are going to 30 meters, you can start at 16-17 meters, you can freefall.
It depends on different factors, it depends on your wetsuit, your body composition, the water where you are diving - fresh water is different than salt water in the ocean. You can do small kicks after the freefalling starts. Let's say that you stop kicking at 16 meters, then you kick again at 20 and then you do another small kick at 24, to keep the speed of the freefall. Or, depending on you, you can just stop kicking at 18 meters and you just glide towards the bottom. This is personal and everybody has his own style.
This advice can change when you are a competitive freediver. Then it becomes a little bit more tricky and there are other tricks and more details. But i just want to give you this general view of the freefalling for basic, intermediate freedivers, going around the 30-40 meters depth.
Body Posture
Another fundamental factor in the freefalling technique is the posture. When you are gliding, after the kicking phase, you should try to find a streamlined posture - trying to stretch your knees, trying to stretch your ankles. If you see your the video of your posture and your body, you should look streamlined and gliding parallel to the line. Then you should pay attention to the position of your head, to keep the head neutral, with the neck aligned with the hand you use to equalize. You should keep hiding your elbow. If you need to equalize frequently, keep the hand and your nose readyto equalize. If you can't hold the equalization for some meters, you can put one hand in the pocket and you can equalize every time you need. If you prefer to have the arrow position with your arms over your head, then you can just stretch it, but be sure that you have the arms totally aligned with your torso.
I see a lot of videos and a lot of students freedivers in competitive level as well, that they stretch the arms in arrow position, but the arms are not aligned with the body. They are diagonal. In the end this is a loss of energy and tension in the shoulders. In my personal opinion, if you are doing amateur freediving or spearfishing, i prefer to put my arms in the sides, for me is more relaxing. When i'm competing with the monofin, of course i have the arrow position, i stretch my arms over my head.
I hope you enjoy these tips and it can be useful for you in your next dives, see you in the blue.
