The owners of two transatlantic communication under-sea cables are seeking High Court injunctions preventing fishing boat owners from trawling near their property.
The action has been brought by GTT Communications Inc and related entities Hibernia Express Ireland Ltd and Hibernia Atlantic Cable System Limited which run between Ireland, the UK, and Canada.
The court heard the cables carries data from some of the largest financial firms, telecommunications firms and cloud operators.
One of the cables carries information key to traders on the global stock markets.
The companies claim that the owners of several fishing vessels have been trawling in the waters near the cables. This it is claimed poses a high risk of damage to the cables.
The companies claim that the defendants' actions also place the trawler crews in danger, as the cables are charged and there is a history of vessels sinking having had their fishing equipment caught in subsea cables.
The cable owners seek various orders against Brendan, Denis, James and John O'Flaherty who it is alleged are the registered owners of several fishing vessels that operate out of Kilmore Quay in Co Wexford.
The orders sought include an injunction restraining them from trawling or dropping anchor or interfering with the seabed within 1 km of their sub-sea cables until the full dispute has been determined.
The applicants claim the cables at risk from the fishermen's alleged actions are the 'segment D cable' which runs from Sutton, Dublin, via the Irish Sea, before making its way west to Halifax, in Nova Scotia, Canada.
The defendants oppose the applications and say there is no basis in law that would allow a court make such orders. The orders would also prevent them from engaging in lawful fishing activities.
Another cable allegedly at risk is the Hibernia express cable, which runs between Brean in the UK, lands in Co Cork, before running on to Halifax.
Ciaran Lewis SC for the companies said the matter was urgent. His clients, following a number of incidents had asked the defendants to cease fishing near the cables, but they had failed to do so.
The cables the court heard are extremely expensive to repair when damaged and varies from €600,000 to €1.4m per repair.
Darren Lehane SC for the fishermen said his clients were currently out at sea, and he was not in a position to give any undertakings to the court till they were able to speak with them.
He said that the matter was complex and should be heard by the judge designated to hear admiralty matters.
The injunction application came before Ms Justice Leonie Reynolds, who said acknowledged the urgency of the matter given the serious claims made in relation to health and safety made by the applicants.
The added that the matter would not be able to be heard until after the Easter vacation.
The matter was adjourned to later this week when the judge hoped that the court would be in a position to fix a hearing date for the dispute.