Marrowstone Island's East Beach Park is a wonderful place to watch ships cruising in and out of Admiralty Inlet. It's also a good starting place for a walk to Nodule Point and the beaches at the south end of the island. But it's a long walk, so I used my bike as a shuttle, allowing me to make my July 4th 5-mile hike a one-way excursion.
The east side of Marrowstone Island is a continuous bluff from the south end almost all the way to Marrowstone Point at the northern tip, except for East Beach, where a broad sandy foreshore has built seaward of the low bluff. It's basically a northward trending spit that diverges from the coastline, then reconnects a short distance north.
I like the terms fringing and looped barriers for these things, but whatever you call them, these wide places in the beach are pretty common on the Salish Sea. Like most barriers, they come in many sizes and shapes. They often form where an abundant sediment supply coincides with a small bend in the shoreline (they occur downdrift of the bend). Sometimes they are a little hard to recognize, since they were prime development spots and are often covered with homes.
The gravel ones tend to be fairly persistent; the sandier ones are much more dynamic. This combines a little of each. The beach and the bars on the lower beach are constantly changing -- the little concrete wall that protects the parking lot has been undermined at times in the past, but this year the beach is way out in front of it.
Google Maps: Aerial View
Ecology Coastal Atlas: 2006 Oblique Aerial Photo