They've got a way to go but the Nigerians are making strides.
Aradu is fully operational again with a new air defense radar; and was in immaculate condition at the Trafalgar review. The ship made the long trip from Africa to Britain & back unassisted (which doesn't sound like much, but is actually a logistical/planning/maintenance accomplishment for 3rd world navies) and this year participated in live-fire gunnery EX'es with the USN. (no firing of Otomats so I don't know if their SSMs are operational anymore).
Their old Lynxes have been replaced by brand-new Augusta A-109E Powers (MH-68A Stingray in USCG service) equipped with FLIR and naval radar. Unlike the Lynx, no ASW but let's face it, there's not much chance of Liberia, Gambia, etc acquiring a sub fleet anytime soon.
In December 2005, they got a squadron of Jian J-7 Fishbeds in an oil-for-guns deal with China to provide coastal air cover.
The USCG just donated two
Balsam class bouy tenders that the Nigerians are converting into OPV's. Not much for combat but they are dirt-cheap to operate, which will free up funds for other modernizations/purchases. They made the 47-day trip unassisted, again showing that the Nigerians are getting their act together with upkeep & repair skills.
As for the rest of the region, I don't know........the USN donated some surplus harbour patrol boats to Cameroon around Christmas last year, and the Togolese seem to be doing a good job of keeping their microscopic navy up to snuff and cooperating. Mauratania just got some coastal patrol helicopters from China. But for the time being Nigeria has about the best thing going in that region.
In addition to piracy, terrorism, threats to oil; it should be mentioned that poaching is a huge problem there. Guinea-Bissau has basically devolved into anarchy. There's a huge fleet of unflagged, unlicensed, unregulated trawlers (mostly ex-Soviet) crewed by locals who clean the ocean out and then resell for cash to larger Chinese fishing ships docked in G-B; who then pile it on to their legal take.