Sec. 15-8a. “Harbor”, “navigable waters” and “navigable waterways”, defined. For the purposes of section 15-8:

(a) “Harbor” means a place on navigable waters where water-borne commercial or recreational traffic enters for the purpose of anchorage or docking or the unloading or receiving of cargo, supplies, equipment, fuel or passengers;

(b) “Navigable waters” means waters which are subject to the ebb and flow of the tide shoreward to their mean high-water mark;

(c) “Navigable waterways” means waters which are physically capable of supporting water-borne traffic, and subject to the ebb and flow of the tide.

Going by the wording of subsection (c) I (me personally) would say that landlocked lakes and ponds (not accessible to tidal waters) would not be navigable waterways. However, as you pointed out in your post the SCOTUS, who are very much higher in pay grade, importance and intelligence then me, have ruled that even shall streams traversable by canoe have met the test. So, going by what SCOTUS is saying, a lake or pond that supports watercraft, like Candlewood, Bashan, Twin, Winchester, etc., could be considered navigable waterways. That being said, as we're talking about a CT state statute, the definition in existing state statutes (listed above) would indicate that lakes and ponds not subject to the tide are not navigable waterways. Now that that's clear as mud, any other questions?

Here's a couple sites if you want to research more:

http://www.americanwhitewater.org/content/Wiki/access:ct

http://www.fairfieldbeachaccess.org/menupublictrust/notableconnecticutcases.html