Helen May 1889. Sign on boat says Boston Seamans Friends, Vineyard Sound Branch Mission Post card.
It clearly shows that the young lady at the stern of the boat is holding a flag with the characteristic entwined C and E of the Christian Endeavor logo.
"In the early years, the local Christian Endeavor Society of the Falmouth Congregational Church worked to help Madison Edwards with his work on the local vessels. They continued to use his boat, the Helen May to go out and visit larger vessels in the harbor in the early work of the Floating Societies as well." A History of the Floating Societies of the Christian Endeavor by Robert A. Danielson. First Fruits Press: 2014. p. 14.