The coast guard had to rescue two groups of people from the water in Dublin last night without sufficient life jackets.
The crew helped a group of kayakers near Sutton as only two people in the group were wearing life jackets.
They later assisted people on a small inflatable boat near Dalkey and found only one person among the group of three was wearing a life jacket.
Irish Coastguard spokesperson Fergus Cooney says people should not go out into the water if they are not properly prepared.
Mr Cooney said: "Trying to get the message out there to people to stay afloat and to stay in contact.
"What we are seeing is an increase of the number of people, which is great, going out on the water.
"What we really want people to get is the message to have a rescue plan in place if something does happen and to make sure they right craft for going out on the water.
"Just have a lifejacket when going out on the water. There's nothing really more to say than that, it's there to save your life."