During long shots of the mock-up of the Mayflower approaching the Fourth of July pageant by ocean, the ship is clearly far out at sea. But in close-ups, foliage from nearby land can be seen just a few feet away.
57:48 That looks like a GMC CCKW 2½-ton 6x6 truck behind the captain's lead Jeep, proceeding to the base on "Route 27", but at 58:09 there's a sign indicating the bridge has a load limit of 1½ tons...