It is a quiet, functional remnant of post-medieval fishing practice, the kind of structure that rarely survives at all, and that most people would walk past without recognising for what it was.

The weir takes a C-shape in plan, constructed from a double row of timber posts interwoven with wattle, the flexible branches or rods woven between uprights in the same manner as a hurdle fence. Downstream braces give the structure added resistance against the pull of the current. The whole thing runs east to west for approximately 47 metres along the west bank of a creek, with its open mouth facing upstream so that fish carried in on the flood tide would be trapped inside as the tide ebbed and the water level fell. A separate horizontal post-and-wattle panel, measuring roughly two metres by one metre, was found buried in the clays about six metres to the east of the main fence. The site was recorded by O'Sullivan in July 2000 and documented in his 2001 survey of intertidal archaeology, which situated the weir approximately 260 metres east of Bush Island. Fish weirs of this general type, using tidal movement to do the work of catching, were once common features of Irish estuaries and river mouths, though relatively few survive in identifiable form. This one, preserved by waterlogged sediment rather than by any deliberate effort, gives a rare sense of the scale and engineering involved in what was essentially an everyday piece of coastal infrastructure.