It is not difficult to figure out where Marino Sanudo and Pietro Vesconte, the writer of the book and the drawer of the map got their information, as Marino Sanudo's book was a history of the crusades and a call for a naval blockade of Egypt plus a new crusade.
The world-map found in this book is clearly based on Arabic sources ; it depicts Africa in a wide truncated fashion typical of Arabic influenced maps, with a passage into the Indian Ocean of roughly 1500 km wide. There are more then 30 copies extant of this manuscript. The inscriptions for East-Africa on this map differ from one copy to the other; I will give a short overview:
On the East African coast can be found ginger (zinziber) and nutmeg (noça) : He connects Ginger (Zingiber) with Zinj. This is a wrong connection as the Ginger tree is from India. It never grew in East Africa. Some 16th century Portuguese however, said it grew in Madagascar and the Comoros (?).On another copy is mentioned : axiba (or ariba) for Zanzibar. The Paris copy of the map has as inscriptions for Africa that do not occur on most other copies: Locaccessim; regio inhabitabilis propter calorem (This region is uninhabited because of extreme heat.) ; Habesse terra nigrorum; Nesc; Chus; Haden; Bedoni; Zinc et imo Zinziber dictur. Zine et ideo Zinzibar on other copies. And these last names stand in front of two towns drawn on the foot of a mountain. Never of his maps is Zanzibar an island, in fact in all cases the two towns and the inscriptions are inland.
Several of the copies of his maps have to the north of Zanzibar on the mainland an area- name called : Bedoni. Easily recognizable as Idris too has a town called Bedouna north of Zanzibar.
Further north again there is a city on the coast called Haden and inland indications of some other cities and Nubia placed north of the Mountains of the Moon and Habashi south. From the text in the book we learn that this is Aden in Yemen.
The Red Sea is called Mare Rubrum ; a name not taken from Arab sources but from classical works.  Some copies of his map show a big island at the mouth of the Persian Gulf called Kis this is the island-town that took over the trade from Siraf in Persia. The crown-like island south of Zanzibar is called Nebio, a name also on Fra Mauro's map (as Nabilah)  and is the Arabic word for Beautiful.   One island has a forest of pepper trees, an other is inhabited by pirates, and a third is called: Insula camar or Linga, dicitur Kamar or insula lince di Camai. This last one we can restore as follows (according to Jules Codine): Insula selindib camar. Which according to Codine means that he has made one island of Ceylon+ Camar. Among the islands in the Indian Ocean is one called Esfacie according to some authors this is close enough to Anfoudja of the Comoros.

If one compares his map of East Africa with the one I constructed from the coordinates given by Abulfeda one can not avoid thinking that they must have used similar sources.
On Abulfeda's map we have the Al-Kerany mountain, this mountain is also present on one version of Marino Sanido's map.
The Nile on Marino Sanudo's map is constructed in the old Ptolemian way, the branch coming from the mountains, closest to the sea is called Nile, the one furthest inland is on one copy of the map mistakenly called (on some copies) flumen Jordan (river Jordan).