crude, crewed

Crude or crude means unrefined or raw, literally or figuratively--
The price of crude oil often makes the headlines.
He was a crude and boorish person, and often gave offense to those around him.

Crewed or crewed is the past tense ( yesterday, or some time ago ) of "crew", meaning to hire or employ a group of people, for work, sport, or military purposes--
He crewed his ship with only the hardiest of sailors.
Crewed may also be the past tense of "crew", meaning to serve as a member of a work, sport, or military group--
The sailor had crewed under this captain before, and knew what to expect.

Now that you know that, you can say--
"The men who crewed the oil tankers were a crude lot, but they got along together fairly well."