During high tide the beach is small and crowded, but as soon as the tide goes out the beach is 3 times larger. The sand is so soft, the water calm, but young people could still use boogie boards to get a short ride. I could see through the water to the sand. You can walk very far out into the water before it gets deep. There are also some small tide pools for young children. They sell and/or rent just about everything one could need for a beach excursion, so if you don't have something with you(such as buckets, boogie boards , sunscreen etc.) it is available for a reasonable price. You do need to pay for parking until 3 pm, after that it is either free or the fee is half price. I'm not sure which one. When we were there the water was in the mid 70s, but I was told it is often in the 60s during July.
If you own or manage Good Harbor Beach, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.