Looking at the tide tables it appears to be a 1.8m tide. 2.1 m tides are expected on 9th March which I suspect will reach or even breach the top of the lock gate.
I succumbed to temptation and visited at high tide at lunch time today. The levels of the water in estuary, sea lock and basin were all much the same as each other; the flood gates were open and all three sets of lock gates were closed.
The tops of the flood gates are (my estimate) about 0.7 m above the structural top of the sea gate, and they are pretty much level with the top of the sea wall.
If the tide goes 300 mm or so above its level today (taking it above the structural top of the sea gate), the flood gates will be closed; but the tide then needs to breach these gates or go over the sea wall to inundate the settlement.
All seems quite serene inside.
Nothing is ever simple and the tide table on display here shows a completely different set of values for high tide compared to the figures cited in other posts here
There are signs with depth markings beside the sea gate,
and they display two sets of depths in feet. Perhaps, the larger figure is the depth of the water in the sea lock ("Ht/m"), and the smaller is the maximum draft of vessel able to pass over the threshold below the gate to enter the sea lock and proceed into the basin? marked in feet and metres.