We had a wonderful stay at Mark's place in Captain Cook. His house is exactly as advertised, large, clean and comfortable. The screened lanai is a particular treat in that it faces the ocean, giving great sunset views, and has a large bed in one corner for sleeping practically under the stars.
The location is pretty good too. There are several good snorkeling sights within 15 to 30 minutes to the north, and Volcano Park is about 80 minutes to the south. The house is in a residential area that is very quiet, cool, and laid back. Much better, in my opinion, than hot, noisy, crowded Kona. The only downside is that there is nothing within walking distance, so you will need a car to get around.
The residential area has its own beach, Pebble Beach, which is a real delight, uncrowded, and great for scuba diving, snorkeling, swimming, kayaking, and all things aquatic. Some guide books say the ocean is very rough at Pebble Beach, and maybe it is sometimes in the winter, but when we were there in July, it was calm as a lake.
Mark is a very responsive and helpful host, as is the ground's caretaker, Adam.
I can't recommend this place highly enough if you are looking for a relaxing stay in a quiet part of the island.