Beachgoers are being warned of sewage pollution at 54 locations across the south west of England.
Much of the country has been battered by heavy rain in recent days, and it has now led to a "sewage pollution alert" for 33 Cornish beaches. There is also a "pollution risk forecast or incident alert" for 21 others, according to Surfers Against Sewage (SAS).
It means around 80% of the beaches in the area are currently polluted.
According to SAS, a pollution alert means "storm sewage has been discharged from a sewer overflow in this location within the past 48 hours". A "pollution risk forecast or incident alert" means there is potential for sewage to be in the area.
Beaches on both the south and north side of Cornwall are affected, including tourist hot spots Looe, Falmouth and Penzance.
Two-thirds of city dwellers wish there were more green spaces in their areaThe main contributing factor to polluted beaches is urban runoff, which sees fertilizers, pesticides, oil, and untreated human and animal waste all entering waterways, such as rivers.
These harmful contaminants eventually end up at our beaches, and with the dirt largely remaining on the surface it can make it dangerous to enter the water, reports Cornwall Live.
Experts at Surf Today suggest waiting 72 hours before entering the sea again after it rains as swallowing water that could be contaminated with fecal matter may lead to a number of illnesses.
Symptoms to look out for include nausea, vomiting, diarrhea, cramps, inflamed stomach and intestines.
Meanwhile, the forecast is for more rain over the coming days in parts of the UK.
A thunderstorm yellow warning is in place from the Met Office for Scotland and northern England while there is also an alert for high winds across the south of England.
A Met Office weather forecast reads: "Today, rather cloudy but mostly dry at first in the north and east. However, locally heavy rain will move northeast from southwest England accompanied by strong to gale force winds. Showers following from the southwest later. Feeling rather cool for most.
"Tonight, rain clearing all but the north of Scotland overnight with showers persisting in the west. Drier elsewhere with some clear spells. Remaining windy while staying rather mild.
"Tomorrow, rain clearing northern Scotland. Sunny spells and scattered showers elsewhere, the showers heavy with thunder possible, most frequent in the west. Another windy and cool feeling day for most."
Beaches marked as pollution risks:
Kingsand
Mum took on British Coal and won battle over choking fumes and poisonous puddlesCawsand
Portwrinkle
Downderry
Seaton
Millendreath
East Looe
Readymoney Cove
Polkerris
Par Sands
Shorthorn Beach
Charlestown
Duporth
Porthpean Beach
Pentewan
Portmellon
Gorran Haven Little Perhaver
Porthluney
Pendower
Porthcurnick
Gyllyngvase
Swanpool
Maenporth
Porthallow
Porthoustock
Coverack
Kennack Sands
Polurrian Cove
Poldhu Cove
Perranuthnoe
Marazion
Long Rock
Penzance
Wherry Town
Porthgwidden
Porthkidney
Gwithian Towans
Godrevy Towans
Portreath
Trevaunance Cove
Perranporth
Crantock
Fistral South
Fistral North
Porth
Mawgan Porth
Porthcothan
Harlyn Bay
Trevone Bay
Polzeath
Trebarwith Strand
Crackington Haven
Summerleaze
Crooklets