There isn't swimming, not in Cebu City itself. The Cebu City waterfront is on reclaimed land that forms Cebu International Port along the Mactan Channel, the narrow strait between Cebu and Mactan islands. It is the largest domestic port in the Philippines and, as is typical, is lined with ferry ports and passenger terminals, docks, piers, shipping yards, tankers, storage, etc.
It is outside of Cebu City proper that you find the gorgeous natural beaches of which this nation of more than 7,000 islands is so justifiably proud.
For proximity, nearest is Mactan Island, connected to mainland Cebu by two bridges (Mandaue-Mactan Bridge and Marcelo Fernan Bridge), and just a few kilometers from the city proper. There, you'll find several public beaches, both in Lapu-Lapu: Maribago (Pajac-Maribago Road) and Vano (Marigondon Beach Road).
As for public beaches on Cebu, the web site of the island, Sugbo.ph, shares these (and a wealth of other resources):
- Logon Beach in Malapascua, 80 km going north of Cebu City, reachable by bus bound for Maya in the North Bus Terminal, and a boat ride in Maya Port to Malapascua.
- Lambug Beach in Badian 100 km southwest of Cebu City. Take a bus bound for Badian in South Bus Terminal. Ask the conductor to drop you off in Lambug, Beach. Then you will need to ride a tricycle or habal-habal to reach to the beach.
- Tingko Beach in Alcoy, perhaps the most popular in all of Cebu, it's 100 km south of Cebu City. At the South Bus Terminal, take a bus going to Oslob, ask the conductor to drop you off right at the beach.
- Basdaku Beach in Moalboal, 100 km southwest of Cebu City. South Bus Terminal, bus to Moalboal, ask to be dropped off in Basdaku. and then ride a tricycle or habal-habal to the beach.
- Hidden Beach in Aloguinsan (literally hidden), southwest 60 km from Cebu City, take a v-hire or van bound for Pinamungajan in Citilink Terminal, ask to be dropped off at Hidden Beach, then ride a habal-habal.
- Matutinao Beach in Badian, southwest 100 km from Cebu City, take the bus to Badian in the South Bus Terminal, ask for drop off in Lambug, then ride a tricycle or habal-habal to the beach.
- Santiago White Beach in Camotes, 90 km north of Cebu City, in the North Bus Terminal, take a bus bound for Danao City, then ride a boat that goes to San Francisco in Camotes.
- Santa Fe Beach in Bantayan, 150 km going north from Cebu City, take a bus bound for Hagnaya from the North Bus Terminal, then the ferry to Santa Fe.