The number of swimming zones have been increased to 37 from last year's 26.
The zones are delineated by a line of red and yellow market buoys.
Infrastructure Minister Austin Gatt told a news conference this afternoon that it is prohibited to navigate any craft in such zones between June 15 and September 30. At the Blue Lagoon, the prohibition started on May 1.
It is also prohibited to secure or moor any craft with any marker buoy and related gear, delineating the swimmer's zones.
The zones are at Paradise Bay, Birzebbuga, the perched beach at Bugibba, Selmun, Ghadira, Rinella, Jerma and Zonqor at Marsascala, St Thomas Bay, St George's Bay, tal-Ghazzelin and tal-Veccja in St Paul's Bay, Golden Bay, Ghajn Tuffieha, Spinola - Sliema, St Julian's and Cavalieri, Hondoq ir-Rummien, Marsalforn, Qbajjar, San Blas, Xlendi, Ramla, Mgarr ix-Xini, Blue Lagoon, San Niklaw, Sta Marija, Main Square Bugibba, It-Tunnara in Mellieha, St Paul's Islands, Gnejna Bay, Armier Bay, Xrobb l-Ghagin, Salina, Delimara Kalanka, Qawra, and Anchor Bay.