With an area of 440 kmē Pulau Banggi is the biggest Malaysian island. It is located at the northern end of Sabah, about 40km northeast of the city of Kudat. About 20000 people live on Banggi, of which 1000 reside in the small city of Karakit, at the southern end of Pulau Banggi. There is a ferry connecting Banggi with Kudat (trip takes about 1 hour, morning and afternoon connections).
Pulau Banggi is densely forested and still completely undeveloped from a tourist perspective. There are cars and roads on Banggi, but no taxis, tourist information or tourist infrastructure whatsoever. Near Karakit there are no nice beaches, so basically tourists who arrive with the ferry are stuck in Karakit with nothing to do. Despite what is claimed on the sensiborneo.com
website, Pulau Banggi is not suitable at the moment as a tourist destination. Also have a look at my trip report
or the "The problem with Pulau Banggi"