Marine diesel at Raby Bay
A canal estate marina at Cleveland, on the shallow southern side of Moreton Bay, with Stradbroke and the southern bay islands directly across the water.
Shallow water, everywhere
Southern Moreton Bay is skinny. Depths across the crossing to Stradbroke and through the island channels are modest, tides matter, and boats regularly work in water where the intake is not far off the bottom.
That produces the defining local engine issue: sand and sediment in the raw water circuit, continuously rather than occasionally.
- Strainers fill faster than owners expect
- Impellers abrade and lose efficiency before they fail outright
- Heat exchangers silt from the inside, with no warning until an overheat
The local adjustment is straightforward: shorten the raw water intervals. Check the strainer more often than feels necessary, clean the heat exchanger before symptoms rather than after, and actually inspect the pencil anode inside it.
Canal berths and short runs
The estate is a canal system, and the characteristic use pattern is a slow run out through the canals, a crossing, and a slow run back.
Prolonged light loading glazes bores and builds carbon, and a boat used this way for years can be in worse internal condition than one with far more hours worked properly. Running the engine up under genuine load regularly is the mitigation, and it has to be deliberate.
Groundings happen here
Shallow water and sandbanks mean touching the bottom is a normal part of local boating rather than a disaster. What is not normal is ignoring it.
After any grounding, check the propeller, the shaft, the cutless bearing and the alignment. Alignment damage in particular shows up months later as vibration or a stern gland that will not settle — and the gearbox eventually pays for it.
Attendance
Canal berthing means mobile servicing is straightforward. Slipping and hardstand are at Manly or the river precincts; book the lift first.
Frequently asked questions
Why do my strainers fill so fast at Raby Bay? Southern Moreton Bay is shallow and sandy, so intakes draw sediment continuously. It is a local condition, not a fault.
I replaced the impeller and it still overheats. The heat exchanger. In this water it silts from the inside and nothing warns you until load exposes it.
Is short canal running bad for the engine? Prolonged light loading glazes bores and builds carbon. Run it up under real load regularly.
I touched a sandbank. What should I check? Propeller, shaft, cutless bearing and alignment. Alignment damage often appears months later as vibration.
Where do I get the boat hauled? Manly or the river precincts. Book the lift before the workshop.