Do I really want to swim in this?

In January I took my PADI Open Water SCUBA training whilst in Tenerife. I can now dive under the ship to clean garbage out of the water intakes, and scrape barnacles off the propeller. But look at the quality of the water here in Cotonou's port. Its absolutely filthy - you can almost walk across it's surface on the floating garbage, and who knows what's in it that you can't see - all manner of nasty diseases I expect. It's a far cry from the beautiful clear waters of the Freeport of Monrovia, where we saw brightly coloured shoals of fish, sea turtles and small sharks. Olly