If you have 6 hours or a half day to spend in Peterhead, there are plenty of things to do:
1. Visit the Peterhead Prison Museum - Learn about the history of one of Scotland's most notorious prisons. This will take approximately 2 hours.
2. Walk along the Peterhead Harbor - Take in the scenic views of the North Sea and watch boats come in and out of the harbor. This will take approximately 1 hour.
3. Explore the Arbuthnot Museum - Discover the local history of Peterhead in this small but interesting museum. This will take approximately 1 hour.
4. Visit the Buchan Braes - Take a walk along the coast and enjoy the fresh sea air. This will take approximately 1 hour.
5. Grab some food at The Harbour Lights - Enjoy some traditional Scottish fish and chips or try out some of their other tasty menu items. This will take approximately 1 hour.
Overall, with some good planning, you can visit all these attractions in the given timeframe.