🔍 Key Concepts

• Hydrodynamic interaction between two tows in close proximity • Effect of upbound current on vessels pushing tows ahead • Which vessel (overtaking vs overtaken) is more affected by disturbed water flow around the towheads

💭 Think About

• Picture two push tows moving the same direction in a river: as one pulls abreast of the other, what does the water between the two towheads want to do—squeeze them together or push them apart? • Think about which tow is in "clean" water and which is in more turbulent, disturbed water as the overtaking maneuver happens. • When a tow has more disturbed flow around its towhead, does that usually make it easier or harder to maintain speed?

✅ Before You Answer

• Be clear on the definitions of overtaking vessel (the one coming from behind) and overtaken vessel (the one ahead). • Visualize the pressure zones and suction effects along the inboard sides of the two towheads as they get close together. • Decide which tow’s engines must work harder due to interaction and current, and which one will be more likely to lose speed.