The Supreme Court's recent decision in Lynn Shellfish Limited v Loose concerned the extent to which private fishing rights extended out into the Wash. The case, in which Bond Dickinson was instructed to intervene on behalf of The Crown Estate, is a fascinating mixture of history, law, aquaculture geography and astronomy.

The main question for the Court was: 'How far seaward did the Lestrange private fishery' extend from the shoreline?'

This required the court also to consider whether, if offshore sandbanks become connected to the shore through siltation of the intervening sea channel, does the fishing right extend over those offshore sandbanks as well?

The Court's answer to these questions is, in part, of general application to all rights over land gained by prescription, not just rights of fishing.


The Lestrange Estate had an ancient right of private fishing for cockles and mussels over an area of the shore in the Wash. This right was not granted by a formal deed, but was admitted to arise as a result of prescription, ie as a result of the private right being exercised over centuries without interference or complaint.

The problem was that, given the right was not given by deed, there was no actual plan of the Wash defining precisely the area over which the private right extended. The issue was of public significance because the public have a right to fish in all tidal waters, save where there is an established historic private right, and thus the more extensive the private right was in the Wash, the less extensive was the right for the public to fish there.

All parties accepted that, historically, the private fishing right had been exercised by fishermen from the Estate going on foot from the land and walking out to low tide to gather the shellfish. However, over the years, the low tide mark had gradually receded seaward as a result of natural forces, but that meant that it was not actually possible for the Estate to show that it had always (over the centuries) used those most seaward areas of the shore more recently exposed.

As any prescriptive claim relies on the claimant demonstrating long use of the right, it was argued against the Estate that their prescriptive right could not possibly extend to more recently exposed areas of the shore which they could not demonstrate long historic use over.

The same argument applied to sandbanks which now were accessible on foot from the shore at low tide as a result of siltation. Were these to be taken as subject to the private fishing right, as they were now accessible on foot (at low tide), or not?

The Supreme Court's decision

Earlier court decisions (both in this case and related litigation last century) had sought to answer these questions by considering what might have been in the mind of a notional grantor of the right, i.e. the monarch as far back as 1189. This was because, where prescriptive fishing rights are concerned, the prescriptive right is based on the legal fiction that long use of the right presumes the grant of it by the monarch in 1189. Thus, one potential way of analysing the actual extent of that right might be to consider what the monarch in 1189 might have granted.

The Supreme Court (perhaps unsurprisingly) was not prepared to entertain this historical fantasy. Instead, the Court asked, what was the extent of the right that the long user demonstrated? As the Estate could demonstrate that the fishing right was exercised over the shore to low water as it existed from time to time, then that was the basis of the prescriptive right that the Estate held.

Given that the court's task was to demarcate the modern day boundary between the competing private and public rights to fish and so needed to specify an appropriate low water mark, the question then was, what, of a selection of accepted possible low tide measures, was the correct one? Was it Mean Low Water, Mean Low Water Springs or Lowest Astronomic Tide (LAT) (a low tide only occurring once every 18.6 years as a result of extraordinary astronomical influences)? Given the flat nature of the Wash, the difference between these different measures was very significant in terms of actual fishing areas.

The Court (not without some hesitation) found that LAT was the correct seaward boundary measure. This was even though (quite obviously) the Estate could not demonstrate a long history of taking fish regularly from the LAT mark as it only was available for fishing every 18.6 years. The Court's decision seems to have been motivated quite significantly by pragmatism, in that any seaward boundary chosen would have a degree of arbitrariness, and any other more landward boundary would have left some shellfish at low tide, on occasions, outside the coverage of the private fishery.

In reaching this decision, the Court was mindful of a general principle relating to prescriptive easements ("the unum quid" principle) that if a claimant could show long use of a right over a particular part of the area concerned, that right would extend to the whole of the area. That meant that the Court was comfortable in their decision that a right shown to have been exercised over part of the shore could be taken, legally, to be exercised over the whole of the shore in that locality.

Offshore sandbanks

Accretion is the principle of foreshore law which states that land that imperceptibly becomes part of the foreshore as a result of siltation or the gradual recession of low tide marks becomes part of the foreshore itself.

The issue for the Court was what happened to offshore sandbanks that become, at a particular moment, accessible from the shore following the gradual siltation of an intervening sea channel.

The Court found that, even though the siltation of the intervening channel had been gradual, the joining of the sandbank to the shore was a sudden event at the point in time when the siltation of the channel was complete. As it was only gradual accretions that are capable of becoming part of the foreshore under this principle, the more instantaneous annexation of offshore sandbanks would not mean they became part of the foreshore.

This meant that arguments that the Estate's fishing right should extend over the conjoined sandbanks were wrong. Those sandbanks, even though now accessible on foot at low tide, would remain available to be fished by the public as previously.


This case is of particular significance to anyone with an interest in rights over the foreshore. However, the way in which the Court analysed the area over which the prescriptive right was available is instructive for anyone faced with questions as to how extensive, in fact, a prescriptive right might be.

However, if that prescriptive right is sought to be exercised against land owned by the Crown as part of The Crown Estate, the Court will not lightly conclude that the claimed prescriptive right significantly usurps already existing rights of the Crown or, on occasions, of the public, e.g. the public right of fishing.