@robz Rob, yes, I believe on these locks there are sluice gates in the lock doors and within the lock chamber, all electrically operated (you can just make out one of the green control consoles on the lock-side to the right of the picture). This lock (being the last one before the river mouth and open sea) is controlled by a lock-keeper, which is quite a rarity nowadays and only seen on those locks which are very complex or large or otherwise strategically important.
