This house is in the middle of nowhere. Look at the map here: http://goo.gl/maps/z0yGR
The house has a spare lot because the lots nearby are also very far from the harbor. There is little demand for these lots even though they are located on a canal. You have to consider that since many canal houses there do not have seawalls, and none of the vacant lots, the canals have a tendency to fill themselves in with dirt. Many of these canal lots are not built upon for over 30 years. Homeowners will have to pay to have the canals re-dredged. If most of the homeowners do not want harbor access, you will be stuck with the bill. The vacant lot owners will vote no on chipping in on paying for dredging as when they want to build when they retire in maybe 40 years, it will need dredging again.
I would examine the canal water depth at low tide with a north wind. Allow for the fact that the time of day for low tide will be way off of published sources; usually the tides run late. Notice how high above sea level the land is located.
Look at the nearby blocks. Dozens of these blocks have no houses. This is because there are so many lots with houses built on them for sale at far less than the cost of building a new house with today's codes which may be on stilts by building time depending how far the lot is above eight feet above sea level. Hurricane codes change. My house was 100% protected in 2010. Then the county changed the protection codes and my skylights dropped my house to 0%. I need a few more storm shutters before I re-new my hurricane insurance in December.
At only 1518 sq. ft. but 17 years old, I would appraise it at $50 per sq. ft. plus MAYBE $50,000 for the lot or $126,000. I would buy a bigger house off water and rent boat storage nearer the harbor for my boat. There are too many unknowns about the canal, and whether the whole canal needs expensive work.
If you buy a train ticket, you pay a FARE. If you do not want to pay too much, you want a FAIR price.