That video is a bad example of how you want to kayak dive. Biggest problem is not having your paddle attached to anything, you should have a paddle leash attached at all times. You do not want to get back to your kayak and find the paddle gone that will make for a long hard swim back to the beach. You want to get as much done while you are still on the kayak as possible not while you are in the water. You want to hang your tank over the side and put the rest of your gear on before jumping in. This includes having your mask either on your face or around your neck, NEVER around the top of your head. That goes for any type of dive, one wave and it is gone not to mention it is about the same as having the word amateur tattooed on your forehead. There also looks like there is a quick disconnect for his air supply, always a bad idea, your air supply is the LAST thing you want to quickly disconnect from. There are also issues with the way the kayak is set up but it is a rental so his choices there were limited. You want everything attached at all times so your kayak should be set up in a way to make that as easy and balanced as possible.