http://www.wannasurf.com has 2 spots in the "waiting room" for Tanzania ... Sea Cliff and Oyster Bay Beach.
http://www.wannasurf.com/spot/Temporary/index.html
Just had a quick look for you guys ... hope it helps. I tried
http://www.surfline.com - before the net they used to produce these mail order surf spot guides for various countries and I checked out a few for NW Africa but I couldn't find any indication that they still produce these.
Then ... the big WWW might help a little if you're up for the big exploring mission. Go find a PC with broadband and download Google Earth
http://earth.google.com/ and start scouring the coastline for anything which may look like it will produce some waves. Google earth allows you to zoom in from looking at the earth from space to being able to make out a few people on North Beach or even tilt to horizontal mode which is like "flyover" mode and the terrain pops up and you can fly along Chapman's Peak, alongside the cliffs, checking out the surf spots and then onto Table Mountain. Pretty cool.
Anyway, below is a screenshot of Dar es Salaam from 7100 ft and at a bit of a tilt which makes it easier to visualise I reckon.
Good luck with the missions ... bring back stories and photos!!!
