I have found that Zillow and some of the other national sites just don't understand "Waterfront" when it comes to value and understanding taxes.
These two sites may help you. The first link is set to search Winnisquam waterfront: both sites have a "Map" option, shows location on the lake.
http://www.nhfinehomes.com/waterfron...am-real-estate
http://nhlakesproperty.com/large-nh-...winnipesaukee/
Other's have given you most of what I would say, but I would add the following:
> Have a good inspection done
> If the property has a Septic system make sure you have money set aside; they can get real expensive on lakefront properties.
> Look up the properties on the local town website and also county Registry of Deeds. It's not easy but with practice you can really trace a property and dig up original development plans.
http://www.nhdeeds.com/belknap/BeHome.html
This is a great site to start understanding what kinds of permits you may need.
https://www.surveymonkey.com/r/shore...Ny%2fvn3hrM%3d
3 years ago with these sites and a lot of internet time, we formally visited just one property and put a deposit down that day. I had been "sort-of" looking for 2 years, but drove by a few when we were renting the last summer, nothing caught my eye. To paraphrase and old saying "let your fingers do the clicking".
Happy Hunting