In Old Dhaka, even the riverway is congested. There are 35 shipyards based in Keraniganj area alone by the side of the Buriganga River. They are part of the approximately 100 shipyards throughout the Buriganga Coast. Meanwhile, 15,000 workers are being employed for this trade. I'd say this is a very conservative number. Further on, if you're just cruising the river, you wouldn't notice this ship congestion.
When I visited the Pink Palace, I had to hop through three ships just to get off the river and on to the palace. There was no adequate space for my boat to dock at. Imagine the riverways in, say 10 years?
This is the Eye in the Sky!