Lake Wellington is the largest and one of the shallowest of the Gippsland Lakes. The waterway is also very exposed to the prevailing weather patterns and can be affected by a significant rise in water levels during flood events and significant lowering of water levels during prolonged high pressure weather system events.
On 21 October 2015 Gippsland Ports carried out a bathymetric survey of the waters adjacent to the Marlay Point boat ramp, pontoon jetty and out to 150m southeast of the breakwater wall. The following average depths to Australian Height Datum (A.H.D.) were recorded.
- Boat Ramp – to a distance of 15m to seaward from the concrete edge of the ramp the average depth is 1.1m (A.H.D.).
- Boat Ramp approach – from the 16m mark to seaward of the ramp out to the jetty head of the floating pontoon the average depth is 0.4m (A.H.D.) at the 16m mark and 0.55m (A.H.D.) at the jetty head (approximately 60m to seaward of the concrete edge of the ramp).
- Boat Ramp approach – from the jetty head to 60m to seaward (towards the North East) the average depth is 0.6m increasing to 0.8m (A.H.D.).
- Average depths recorded for the seaward approach from the East towards the breakwater and boat ramp facility varies progressively inbound from 1.3m to 0.7m (A.H.D.).
- At the inner face of the pontoon jetty (NW side) the average depth is 0.4m (A.H.D.).
- At the outer face of the pontoon jetty (SE side) the average depth is 0.2m (A.H.D.).
- At the L shaped jetty head of the pontoon the average depth is 0.45m approximately (A.H.D.).