Castletownbere fishing port is undergoing major works including installation of new breakwaters and major dredging that will last until Spring of 2020. If you are planning to stop there, proceed instead to Lawrence Cove on Bere Island or to the new marina in Bantry.

Vice Commodore, OCC 

Hi all, Castletownbere was very pleasant to visit, but looked challenging for visiting recreational vessels. We visited from the island of Bere by their very short ferry while enjoying what Bere had to offer. Please see our Alchemy Harbour notes below.
My best, Dick Stevenson, s/v Alchemy
Bere Island, Lawrence Cove Marina
We found deeper water than charted coming in. This is a delightful family run marina/boatyard on a great island. Rachel takes good care of you. They even have a couple of junker cars you can sometimes borrow; the island has few rules and no police, and, you may notice, no up to date license plates for the cars that never leave the island. We had use of the cars all the time because it was so early in the season. In any case the car made some long and beautiful walks possible: Doonber Loop and the loop out to the lighthouse at the west end (see intro section on Looped Walks). And just driving around the island was eye candy. The small town is within walking distance.
Castletownbere
We took the ferry to visit from the west end of the island. The town was delightful. Very alive and with a good mix of stores, pubs and restaurants. Try the brown bread at Jack Patrick and then buy a loaf or two. There is a pontoon, but it was 90+% filled with commercial boats. One of the rafted recreational yachts we saw later said they only stayed an hour and felt unwelcome. The area where anchoring was recommended was empty but certainly looked possible.