Among the first thing they learn in this voyage is how to perform a proper blowjob. Slavers don't have time for finesse, all that matters is the crew to be serviced fast and the rowing to start.
End of the sea voyage. From the port to Dulla, the end destination there's a scorching desert that slaves has to pass chained and restrained. Heavy wooden yokes are placed on the shoulders of the slaves.
The heavy weight oif their restraints makes a few slaves to almost tumble and fall. The guards, aware of that are at hand, ready to help them back on their feet. In a few days, slaves will carry their bonds much better.
Before going into the desert, chains are checked, locks are tried, supplies are counted and recounted. Aside from a few oasis, there will be scarce water available till Dulla.