Gareth Morrison, RNLI head of water safety, urged swimmers to be aware of risks, check sea conditions, understand their own limitations, and consult a GP if they have health conditions.
The RNLI advises swimming with others, staying in depth, wearing wetsuits, bright caps, and tow floats, and crucially, calling 999 or 112 for the coastguard instead of entering the water to help someone in distress.
While some festive swims were cancelled due to severe weather, organised New Year's dips, such as those in Westward Ho! and Salford Quays, are proceeding with stringent safety measures in place.