The search for a swimmer reported to have been in distress off WA's South West has resumed.A witness reported a woman in distress in the water in Bunbury's Koombana Bay, about 170 kilometres south of Perth, just after 9:20am on Wednesday.The woman has not been seen since.Bunbury officer in charge Senior Sergeant Bernie McConnachie said water police were searching the area by boat this morning.Police launched a major ocean search yesterday, but were unable to locate her.Divers were part of the search on Wednesday, but Senior Sergeant McConnachie said she was not aware of them being part of the search today.She said police had not received any reports of someone going missing after going for a swim."It's just incredibly important that people check in with people they know go swimming in the area so that we can identify any people that we might be looking for because we've been unable to confirm any missing persons as yet," Senior Sergeant McConnachie said."But obviously it's been incredibly important that we act on the information supplied to us and we'll always deploy where we believe that there's a risk to community safety."Whether or not the swimmer remained in distress is still a mystery to police, she said."They appeared very confident in the water And then the next minute they were gone," Senior Sergeant Mconnachie said."So it just remains incredibly important for people to check in with people that go swimming in that area