All depends on a number of things. In terms of distances at high tide it's about 1.5 miles from either launch to the north end of North Monomoy, 3.5 miles to the north end of South Monomoy and around 9 miles to the south end of South Monomoy. These distances increase greatly at low tide since you would have to paddle around the flats. If you plan your trips around the tides and go with the flow, your paddle out and back will be much faster than if you end up dogging it against the current. My usual trip is to circumnavigate North Monomoy and I usually allow the whole day. If your short on time stay up in the bathtub to the west of South Beach since there is plenty of good fishing there too.