If I remember correctly the Gut is part of the original waterway of the Coquet before it changed its course. It was in effect a big southerly meander in the Coquet's course to the sea further north. Swept round under Gloster Hill.
Back in the day, pre Marina, the Braid used to be the Council rubbish tip. The bin lorries...small grey things with a lidded container, one either side were filled with mostly ash from coal fires, it seemed like, and all dumped down on the Braid