Yes your right. The weight a sailor carries changes the equipment that works the best. Take an example: 100kg beginner sailor might choose a 180L board (80L above body weight), an intermediate would move to 130-150L board (30 to 50L above body weight), and advanced can range from 90L to 110L (similar to body weight). But also note that even advanced sailors choose bigger boards and sails in light winds. Its a very technical sport but alot of fun and challenging, you will love it.. FYI im a lightweight sailor at 70kg, which may help you understand the video a bit easier.