Great Teaching Aid, But Fills Up With Water

I bought two of these floats a few weeks ago and have been very happy with them overall. I used them as a training aid for kayaking lessons in a pool and it was a huge help in learning the paddle strokes for rolling. My only complaint is that the pocket for the paddle blade tends to fill up with water which makes it very heavy. I’ve considered cutting a few small holes in the bottom for the water to flow out but don’t want the whole thing to tear...