I guess I'll start off talking about the job I end up doing more often then not; driving semi. There are several names for this job like UTR (I forget what it stands for), yard hustler, and container jockey. Much of my time on the docks has been behind the wheel of a semi. As a B-man (second tier in the longshoreman hierarchy) we get second pick of the jobs after the A-men and are obligated to fill the skilled work like semi before non-skill jobs.
Just because you can drive a car doesn't mean you can drive a semi. While really quite simple there are several notable differences. Immediately you will notice the lack of visibility. There is no rear view mirror, so when hauling a container on your chassis (metal frame trailer with wheels upon which cargo containers are placed so that they may be transported) you will rely on your side mirrors to see behind you. This can present some challenges when parking chassis especially in the rain. It's also really important to notice that the amount of space used to turn is much larger when hauling a chassis. Ever seen a semi driver on the road make a right turn? If you haven't or just weren't paying attention you would see them possibly taking up both lanes of the road to just barely make that right turn. That's because the trailer doesn't perfectly follow the semi. It follows a tighter turn radius. So if I make a turn too close to something my trailer I could run right into someone or something. Wide turns are your friends when behind the wheel. Probably one of the most difficult things to do in a semi is park a chassis. When I first started I was really quite awful at it. To get into a parking spot you must reverse into a space with maybe two feet on either side of your container. Doing this while the parking slot is on your left hand side is considerably easier because you can stick you head out the window and know exactly where your trailer is headed. But if the spot is on your right there are points in your turn where you can't see much of anything and really must rely on your own good judgement and experience to get you into the spot.
As a semi driver it's your job to transport containers. That could be from the ship to the yard or from the yard to the ship, and in other cases from the yard to another yard location. If you're working with the ship discharging containers to the yard, your first task would be to get a container from the crane (who is taking containers off the ship). Once the container is placed on your chassis you then drive out to the yard location assigned to the container and told to you by the checker. Once you get there you either park the container or line up at the spot and let the top pick (huge forklift that picks up containers from their top or roof and stacks containers on top of each other like legos or building blocks) take the can off you. You drive back to the crane and it all starts over again. You've done one lap. When loading the ship the exact opposite happens. As always there are thousands of small details about the job, but I think that pretty well sums it up.