Challenges with LSFOs at sea
LSFOs slick behaviour
LSFO slicks at the sea surface may behave differently than conventional oils depending on the LSFO’s physical properties and temperature (and environment?).
LSFOs may appear as either fluid, semi-solid or solid slicks at the water surface.
This is highly related to the variability in pour point of LSFOs. Some LSFOs may not form a slick at all but appear as small solid lumps in the water.
Some LSFOs can be submerged in the water column, and reappear to the water surface, creating challenges with detection and containment. (experiences from spills: Netherlands, Gibraltar, Sweden (?))
Use of chemical dispersants have shown little effect on several LSFOs, much due to (Cedre’s conclusions about dispersability) Flammability of LSFOs is generally X and in-situ-burning is X. 
Solid or semi-solid oil slicks can have varying thickness throughout the slick, where the thickness is often highest at the far edge of the slick, furthest away from the boom. These slicks may also roll at the edge and accumulate at the far edge from the forces of the water current, which does not allow for large concentration of oil near the apex of the boom.
LSFO’s poor flow properties for recovery equipment
LSFOs may exhibit poor inflow and low adhesion to oleophilic skimmer surfaces and recovery equipment.
Some LSFO’s behaviour at sea causes poor inflow to the skimmers, due to properties such as solid or semi-solid oil slicks or lumps, low adhesion to oleophilic surfaces, or the oil having “short” properties where the oil would not continuously float towards the skimmer during recovery.
Oil bridging in front of skimmers or other obstacles can occur, preventing oil flow into the skimmer.
Solid/semi-solid LSFOs may stick to the sloped sides of the hopper’s walls, thus preventing it from reaching the pump.