There's a report in Tanzania's Daily News about DRC business representatives pushing the Dar es Salaam port authorities to speed up their clearance of goods. The senior representative noted that Congolese businesspeople have access to other ports, notably Cabinda in Angola, and these ports are improving. The Tanzanian authorities said there were trying to improve things, so it is nice to see that competition is working as it should.
I don't have access to relevant statistics for Cabinda, but I do for other ports. A company survey from 2006 found the following average statistics for Dar es Salaam exporters:
Time to clear customs: 6.3 days
Value lost through theft: 3.0 percent
Value lost through breakage or spoilage: 2.9 percent
For companies operating in the major west coast ports in Luanda (Angola), Cotonou (Benin), and Pointe-Noire (Congo), the statistics (in 2009-2010) were:
Time to clear customs: 10.4 days
Value lost through theft: 2.8 percent
Value lost through breakage or spoilage: 2.7 percent
It looks like Dar es Salaam was outperforming these ports. However, look at the statistics for the Kenyan port of Mombasa in 2007:
Time to clear customs: 2.5 days
Value lost through theft: 0.5 percent
Value lost through breakage or spoilage: 0.3 percent
Assuming the data is reliable, it makes me wonder why Mombasa is not a stronger contender for the DRC's exporters (I seem to remember that it may have been in the past). Perhaps the border crossing between Tanzania and Kenya is a headache for them.