Some Singlish vocabularly actually derives from nautical English. The port has been important for a long time.

See eg https://www.angmohdan.com/origins-of-gostan/ (and also http://www.mysmu.edu/faculty/jacklee/singlish_G.htm)

I lament that most people speaking to an ang moh like me code-switch to the Queen's English instead of sticking to proper Singlish.