Beach conditions across the Mornington Peninsula and Frankston are mixed for the week ahead, with three key issues to plan around.
A reported shark sighting at Portsea Beach on 28/12/25 is prompting extra caution for swimmers, surfers and paddlers, particularly on open-coast beaches.
A South East Water sewage spill advisory remains in place for Sweetwater Creek and Frankston Beach, with the public advised to avoid water contact in affected areas.
Bluebottles and jellyfish sightings are continuing across multiple Peninsula beaches, with stings still being reported.
UV levels are expected to be Extreme (around 11), with sun protection recommended from about 9.00am through late afternoon.
Alerts and safety notices
Shark sighting
- Current status: Recent public report
- Area: Portsea Beach
- Date and time: 28/12/25 at 1.59pm
- Source: Dorsal Watch community report (Report ID 47405)
Practical advice: If you see a shark or receive credible advice of a nearby sighting, leave the water calmly. Avoid swimming alone, avoid dawn and dusk where practical, and follow directions from lifesavers and emergency services.
Marine stingers: Bluebottles and jellyfish
- Trend: Ongoing
- Areas affected: Reported across multiple beaches from Frankston and Seaford through to the lower Peninsula
- What it means: Bluebottles can sting in the water and on the sand, even when washed up
Safety guidance: Avoid swimming where bluebottles are visible in the water or along the shoreline. Supervise children closely, consider protective swimwear, and keep dogs away from washed-up bluebottles.
Water quality and pollution advisory
- Issue type: Sewage spill advisory
- Locations: Sweetwater Creek and Frankston Beach
- Authority: South East Water
- Current advice: Avoid water contact in affected areas, including for pets, until water quality testing and clean-up are confirmed complete
- Background (as advised): Overflow was reported from a sewer incident in Frankston South into Sweetwater Creek and the Frankston foreshore area
If you are heading to Frankston Beach, check for advisory signage on arrival and consider choosing an alternative location away from creek outlets.
Weather and surf hazards
Weather and UV outlook (BOM)
Frankston South (BOM): Sunny conditions with a hot afternoon expected, and UV forecast to peak at Extreme levels (around 11).
Flinders and Mornington Peninsula (BOM): Sunny conditions with sea breezes developing later in the day, and UV forecast to peak at Extreme levels (around 11), with sun protection recommended from about 9.00am to 5.40pm.
Surf and water hazards
- Afternoon sea breezes can increase chop and make conditions more difficult for weaker swimmers and inflatables
- Open-coast beaches can carry stronger currents and rips even when conditions look calm
- Holiday crowding increases the risk of lost children, collisions in the shallows, and delayed help when incidents occur
Practical advice: Choose a patrolled beach where possible and swim between the flags.
Conditions outlook
- Temperature pattern: Hotter conditions are more likely in Frankston and bayside areas, with coastal cooling possible across parts of the Peninsula when sea breezes strengthen
- Winds: Breezes are expected to shift during the week, which can change surf exposure quickly on open beaches
- UV: Extreme UV is forecast on multiple days, with peak exposure typically late morning to mid-afternoon
- Rainfall impact: Even light rainfall can temporarily reduce water quality near stormwater drains and creeks
Patrols and beach access
Patrol availability varies by beach and day during the holiday period. For confirmed patrol locations and times, check BeachSafe before you leave.
General reminder: Swim between the red and yellow flags and supervise children at all times.
Regional beach round-up
Frankston and Seaford
- Key hazards: Sewage spill advisory near Sweetwater Creek, bluebottles
- Water quality status: Avoid water contact in affected advisory areas and near creek outlets
- Patrol notes: Check BeachSafe for patrolled locations and hours
Mount Eliza and Mornington
- Key hazards: Bluebottles, holiday crowding
- Water quality status: Generally typical for summer conditions away from drains and creeks
- Patrol notes: Check BeachSafe
Mount Martha to Safety Beach
- Key hazards: Bluebottles and jellyfish activity
- Water quality status: Generally typical for summer conditions
- Patrol notes: Check BeachSafe
Dromana to Rosebud
- Key hazards: Marine stingers, crowded shallows
- Water quality status: Generally typical for summer conditions
- Patrol notes: Check BeachSafe
Capel Sound to Rye
- Key hazards: Bluebottles, higher beach numbers during hot afternoons
- Water quality status: Generally typical for summer conditions
- Patrol notes: Check BeachSafe
Blairgowrie to Portsea
- Key hazards: Recent shark sighting (Portsea, 28/12/25), plus marine stingers
- Water quality status: Generally typical for summer conditions
- Patrol notes: Check BeachSafe and follow local lifesaving advice
Surf beaches
- Key hazards: Rips, shore dump, changing surf conditions, bluebottles
- Water quality status: Generally typical for summer conditions, with localised changes after rain
- Patrol notes: Choose patrolled beaches and avoid isolated stretches
Before you go checklist
- Check current warnings and advisories
- Check water quality forecasts
- Choose a patrolled beach
- Swim between the flags
- Avoid swimming after heavy rain
Sources and transparency
Sources referenced for this report include:
- Bureau of Meteorology (local forecasts and UV guidance)
- South East Water (public sewage spill advisory information)
- EPA Victoria Beach Report and water quality guidance (for checking conditions)
- Surf Life Saving and BeachSafe (patrol guidance and beach safety messaging)
- Dorsal Watch (community shark report listing)
This report reflects information available at the time of publishing. Coastal conditions can change rapidly.
If you notice changing conditions or hazards, contact STPL News with the beach name, time and details.
