Alan, I live in Milford too. I've done that trip.
It can be done in one day, but given the normal summer light winds, you'll have to motorsail to do it in a day. My personal best sailing was a 9:30AM start from Mystic Shipyard with a 6:30PM arrival at the Anchorage off Charles Island. I hit the tides and wind perfectly in order to do it. I have a H29.5.I would check the mileage on the charts. It seems to me that it's farther than 43 miles.It's about 70-75 statute miles by car on I-95 which is a pretty straight shot. My charts are on the boat, but I checked Eldridge which lists 59.9 miles to Ram Island from Stratford Point. You'd have a run up the river to Mystic of a couple miles from there. I would guess it's closer to 60nm.If you want to sail, a logical stop off is in Clinton where there is a pool for the kids and a small restaurant in the Marina. You can make it in a 2 day relaxed sail easily without any sweat.Check Eldridge for currents because Mystic is East of the Race. A helping current up to the Race hinders you after you pass the Race and vice versa.If they put you on the North side of Mystic Shipyard's docks, stay within about 50-75 ft off the docks when entering/leaving. There's a mud shoal just North of the docks. Just don't ask me how I found out.Mystic Seaport is a short distance away, Mystic Aquarium a little farther. The kids will definitely find something that interests them.If you have any other questions, give me a call, I'm in the book.