||Bridge and Lock Tenders
- Observe approaching vessels to determine size and speed, and listen for whistle signals indicating desire to pass.
- Observe position and progress of vessels to ensure best use of lock spaces or bridge opening spaces.
- Maintain and guard stations in bridges to check waterways for boat traffic.
- Check that bridges are clear of vehicles and pedestrians prior to opening.
- Raise drawbridges and observe passage of water traffic or lower drawbridges and raise automobile gates.
||Air Traffic Controllers
- Monitor or direct the movement of aircraft within an assigned air space or on the ground at airports to minimize delays and maximize safety.
- Monitor aircraft within a specific airspace, using radar, computer equipment, or visual references.
- Check conditions and traffic at different altitudes in response to pilots' requests for altitude changes.
||Sailors and Marine Oilers
- Stand watch in ships' bows or bridge wings to look for obstructions in a ship's path or to locate navigational aids, such as buoys or lighthouses.
- Stand gangway watches to prevent unauthorized persons from boarding ships while in port.
- Participate in shore patrols.
- Observe train signals along routes and verify their meanings for engineers.
- Observe tracks from left sides of locomotives to detect obstructions on tracks.
||Rail Yard Engineers, Dinkey Operators, and Hostlers
- Observe and respond to wayside and cab signals, including color light signals, position signals, torpedoes, flags, and hot box detectors.
- Spot cars for loading and unloading at customer locations.
- Monitor street or utility projects for compliance to traffic control permit conditions.
||Mates- Ship, Boat, and Barge
- Stand watches on vessels during specified periods while vessels are under way.
- Observe tracks to detect obstructions.
||Tank Car, Truck, and Ship Loaders
- Observe positions of cars passing loading spouts, and swing spouts into the correct positions at the appropriate times.
||Ship and Boat Captains
- Perform various marine duties, such as checking for oil spills or other pollutants around ports or harbors or patrolling beaches.
||Parking Lot Attendants
- Patrol parking areas to prevent vehicle damage and vehicle or property thefts.
||Airfield Operations Specialists
- Monitor the arrival, parking, refueling, loading, and departure of all aircraft.
||Railroad Conductors and Yardmasters
- Observe yard traffic to determine tracks available to accommodate inbound and outbound traffic.