Lake Crescent is about 2 and one half hours from Eight Diving and a beautiful gem of a lake on the Olympic Peninsula. You need to head towards Port Angeles and then drive about another 30 minutes west into Olympic National park. It’s easy to find it on a map or in your navigation in your vehicle. The lake is very low in nitrogen so that means that it is not choked with weeds or any other flora. There are quite a few trout in the lake and you will likely see them diving.
What makes Lake Crescent special is the visibility and the warmth in the summer. The water temps can get up to 65 degrees in the top 30 or so feet, which is nearly tropical for us in the PNW! Down deeper though it gets even colder than the ocean with 44 degrees or so at depths below 100 feet. The visibility can be nearly tropical and I’m sure it approaches 100 feet. The lake is also very deep with depths in the sub 500 foot range recorded. The underwater topography is very interesting in some places with sheer clay and rock walls dropping into the depths. Sledgehammer wall is deeper than 300 feet and a very nice technical scooter dive. East Beach is a nice place to explore recreational depths and nearly every pull out along the side of the lake lends itself to recreational diving. There are also two famous wrecks in the lake for technical divers: 
the Warren car at about 165 feet and the Steele car at about 190 feet. The appropriately certified diver can dive both of them on one dive with a DPV if they are so inclined.
Several instructors like to use the lake for special events or when the ocean and Lake Washington are weathered out. It is a longer drive but worth it!S