Oh boy, you know something has a very limited service if they don't even include it in the route name!
GATRA's Link 4 runs not only between Cranberry Plaza and some intersection in West Wareham, but has peak hour trips to the Middleborough / Lakeville train station (which, oddly enough, GATRA calls it the Lakeville MBTA Station, too bad the Lakeville portion will be gone in 2023). Reminds me of the WRTA B.
For most of the day, the Link 4 operates as a shuttle between two shopping plazas in Wareham. In addition to those two, this route technically has five termini with the multiple service patterns. One northbound (northbound or westbound, what do I call this?) trip (the 5:55 am departure) goes all the way east to Buzzards Bay. The 7:05 am northbound trip starts at Onset Pier, which is also served by the Buzzards Bay trip, and a trip arrives at Onset Pier at 6:45 pm. The Commuter Rail station gets 4 northbound arrivals (2 in the morning, 2 in the late afternoon) and 3 southbound (or eastbound?) departures (1 in the morning, 2 in the late afternoon). All other trips run between that intersection in West Wareham and the Cranberry Plaza. Trips run every hour in this section between 8 am and 3 pm. The route runs every 2 hours for the last two trips.
Also, GATRA doesn't give me any information on the website about what "R" and "RR" on the online schedule mean. Probably something with request service, but GATRA doesn't list the time the bus would be near these stops! I can't tell if that last southbound trip (the 6:10 pm from the train station) makes all the local stops or not. I'm assuming it does.
The route isn't any better on Saturdays. Schedule is cleaner, though. Four trips, every two hours, 9:30 am to 3:30 pm. Just between the intersection in West Wareham and the Cranberry Plaza.
GATRA's Wareham routes (Link 1, Link 2 and Link 4) all use Cranberry Plaza as a hub for the Wareham area. It's quite a good hub for this mini-system. It's centrally located and a major destination for people in town. It's also a short bus ride away from Onset and Wareham Village as well. A connection to the Downtown Middleborough Shuttle is also available at the train station.
Final thoughts - I mentioned at the start of this post that it is similar to the WRTA B. Compared to the B, the Link 4 is better. It does the same exact thing as the B, but just better. Similar hours (but including Saturday service), connects with routes at Cranberry Plaza, and has well-done round trips from the train station. My biggest irk with the B was that a lot of trips from the Grafton train station were closed-door expresses, but the Link 4 makes all the stops on the way back. My suggestions are similar to what I had in B, But Better. The route should probably improve service to the train station, probably through a midday trip and weekend service.