LAKE CRESCENT — Yes, there really is a submarine cruising Lake Crescent this week.

The sub, built by U.S. Submarines, is among the first personal submarines being offered to the public for the price of $640,000.

The submarine, christened the S-101, will be cruising the lake’s clear waters at least through Thursday during a shakedown test by the craft’s builders.

Lake Crescent was chosen for the tests because of water clarity, company co-founder Ellis Adams said.

Lake Washington near Seattle and Puget Sound are too turbid for submersion testing, he said.

Built in 1987 and recently refurbished, S-101 is 32 feet long and constructed of steel and acrylic.

It can dive to a depth of about 300 feet holding two passengers and payload, Adams said.

It has a range of about 200 miles under diesel electric power.

Production versions of the S-101 will be able to dive up to 1,200 feet beneath the surface, according to company specifications.

A collection of curious bystanders watched as the sub was hoisted by crane from a flatbed trailer and placed in Lake Crescent’s cold water near the Log Cabin Resort on Tuesday.

Nearly everyone had a camera to record the event.