Transcript for Visual Guide to Water Dynamics and Features
A montage of water rescue scenarios is shown.
You are looking downstream. You see the laminar flow, traveling away from you, and the helical flow to river left. Next, you see river left on the left side of the screen and river right on the right side of the screen. After that, you see the outside bend to river left and inside bend to river right. The laminar flow is still traveling away from you as it follows the river bend.
You are looking upstream. You see the laminar flow, traveling toward you, and the helical flow to river right. Next, you see river right on the left side of the screen and the river left on the right side of the screen.
Upstream and Downstream Vs
You are in a raft with another rescuer in front of you. The rescuer points to the downstream V ahead in the open channel. There is also an upstream V obstruction on the other side. The lower unit of the raft strikes against a rock.
Eddy, Eddy Line, and Sweeper
You see a group of three rescuers in an eddy with the eddy line shown. A person swims toward the group across the eddy line.
You are in a raft with another rescuer in front you. You see the sweeper behind the raft. While you are facing forward, you see the eddy and eddy line to the side.
You see a warning sign indicating that there is a low-head dam ahead. The horizontal line going across the river indicates that there is a drop ahead.
You see the outwash, flowing away from low-head dam, and the boil line that separates the backwash from the outwash.
The recirculating hydraulic at the base of the low-head dam is often called a drowning machine.
You see the strainer just below the surface, indicated by the horizontal line. You go over two strainers.
You see other strainers that are created by branches.
Pillow and Undercut
You see a pillow. You also see an undercut, indicated by the fact that there is no pillow.
What Do You See?
You are in a raft with another rescuer. You see...
Could This Area Flood?
You are driving down a road in a town during the day. The roads are clear.
It is nighttime at the same location. You are walking on the road with other rescuers. The roads are flooded.
You are driving down a road in another town during the day. The roads are clear.
It is nighttime at the same location. You are looking at a whirlpool in the middle of the street.
You are looking at the source of the whirlpool during the day.
You are looking at the source of the flash flooding during the day. It is water under a street.
You are driving on a country road during the day.
It is nighttime at the same location. You are walking with another rescuer. Never assume the road is there. Always use a paddle to probe ahead.
A montage of water features is shown.
For more information contact:
Boating and Watercraft Safety Manager
PA Fish and Boat Commission
1601 Elmerton Ave. - PO Box 67000
Harrisburg, PA 17106-7000
Search “PENNSYLVANIA WATER RESCUE”
Copyright: PA Fish and Boat Commission
Video by: Chris A. Calhoun