Time to show symptoms
12 hours to show up food poisoning? More like 2 to 4, depending on the severity.
Long ago I had a Captain who shortly after climb was more or less incapacitated due food poisoning from his breakfast in Khartoum.
He had been trying to persuade me to eat the same hubble bubble - "delicious" he said.
The rest of the story is not really to my credit, as the FE and I brought the ship back to Europe, while the Captain monopolised the toilet. Had we known how long he was going to be out of service, we should have gone down earlier.