From the excellent folks at the International Chamber of Commerce Commercial Crime Services International Maritime Bureau's Live Piracy Map, IMB Piracy & Armed Robbery Map 2018 a look at how piracy and armed robbery looked in 2018 as compared to 2017:
Drilling down to the area offshore Nigeria in the Gulf of Guinea for 2018:
And in the South China Sea Region:
Worth noting that the Arabian Sea especially off Somalia, once a hotbed of piracy, has not been very active in either 2017 or 2018.
On the other hand, the war in Yemen has spilled over to impact some shipping, as has been noted throughout the year.