After conducting research, I was unable to find information regarding a boat ramp named Main Street Poughkeepsie at the given latitude and longitude coordinates. However, I did find information on a boat ramp located in Poughkeepsie, New York, which may be the one in question.

The Poughkeepsie boat ramp is located at Waryas Park, which is accessible from 1 Waryas Park Promenade, Poughkeepsie, NY 12601. It provides access to the Hudson River and is suitable for small boats, canoes, and kayaks. The ramp is said to be approximately 14 feet wide, which is enough for a single vehicle to launch and retrieve a boat at a time.

According to the official website of the City of Poughkeepsie, the boat ramp at Waryas Park is open from April 1st to November 30th, from dawn until dusk. A daily launch permit is required to use the ramp, which can be purchased at the Poughkeepsie City Chamberlain's office or the Poughkeepsie Police Department. Additionally, a seasonal permit is available for those who plan to use the ramp frequently throughout the boating season.

In terms of the location, Waryas Park is situated on the eastern shore of the Hudson River, just south of the Mid-Hudson Bridge. It is a popular destination for boaters, fishermen, and picnickers, with plenty of parking and amenities such as restrooms, picnic tables, and grills.

To summarize, the boat ramp located at Waryas Park in Poughkeepsie, New York is approximately 14 feet wide and provides access to the Hudson River for small boats, canoes, and kayaks. It is open from April until November and requires a daily or seasonal permit to use.