The Irish Coast Guard has seen a major growth in demand this year, with a 30% jump in the number of distress calls.
The search and rescue service has been called out to a total of 1,763 incidents so far this year, an increase of 400 from the same period last year and 150 more than any year over the last five.
It came as Transport Minister Hildegarde Naughton urged people to follow basic safety measures when taking part in coastal or water activities over the Bank Holiday weekend.
She said members of the public are advised not to take inflatables on to the water.
On Monday, a man spent almost 11 hours in the water in Co Louth after his inflatable dinghy capsized.
The man, in his 40s, was rescued on Monday night after he drifted out to sea at Whitestown Beach in Dundalk.
A number of groups were involved in the rescue, and the man was taken to Beaumont Hospital in Dublin.
A combination of good weather and restrictions on other recreational activities has seen an “extraordinarily” high level of participation in coastal and water-based activities, according to Ms Naughton.
The number of people visiting beaches and coastal areas is expected to rise this August Bank Holiday weekend.
Ms Naughton made the water safety appeal alongside staff and volunteers from the Irish Coast Guard and the RNLI in the wake of seven water tragedies in seven days.
“Tragically, last week we saw a total of seven drownings on the island of Ireland in seven days, the majority of which were on inland waterways,” she added.
“I would like to offer my sincere condolences to the loved ones of those we have lost at sea on their heart-breaking and untimely loss. This loss of lives in as many days provides a stark reminder to us all as to how quickly serious accidents can happen.
“This Bank Holiday weekend we can all make personal decisions which will go a long way towards staying safe in the water, such as ensuring that swimmers are accompanied, and letting friends or family know your planned return time.”
The public has been asked not to use inflatable toys on the beach or inland waterways; swimmers should always ensure that they are accompanied or that their activity is being monitored by someone ashore; and open water swimmers should wear a high-visibility cap.