The guide will be useful only to Cape May. From there to Block the guides are pretty silent. If Block really is your destination then hang in Cape May and wait for a S wind. Anything less than 25-knots will be a pleasant ride in a 49 foot boat. It is 208-nm anchorage to anchorage Cape May to Block Island's Great Salt Pond. Our last trip back was 29-Hr, 13-min, but that was unusually quick for our smaller, 39 ft boat.
the winds from the S will be more dependable by May-June. If you do go in a N wind - the trip is longer (hours and miles) and can get tedious if the boat is punching through waves hour after hour.
In the summer there is enough variation in the wind that if you listen to NOAA Wx radio you will be able to get a N wind back to Cape May.
Go in and edit that Title line from Black
Island to Block
Island and you may get some more advice on the topic from others