Emergency services were spotted by a river after receiving reports about the incident.
The area was also cordoned off by the fire service.
The RNLI lifeboat was also seen on the river carrying out a search following the incident on the River Arun in Arundel.
A person was seen being tended to by the ambulance service after receiving a wound to the leg.
A coastguard spokesperson said: “HM Coastguard has been responding to reports of two people in the water in Arundel today, 31 July. Alerted at around 4pm, Littlehampton Coastguard Rescue Team and a lifeboat from Selsey RNLI were sent to the scene, alongside fire and rescue service and ambulance service.”
A Secamb spokesperson said: “We were called at approximately 4.30pm to reports of two people falling from a boat. Ambulance crews attended and two people were assessed and treated before being discharged from our care at the scene.”
A spokesperson for West Sussex Fire & Rescue Service said: “On July 31 two fire engines, two off-road vehicles and a service boat dealt with an incident near the Old Town Bridge in Arundel following reports of a person in the water.
“The initial 999 call came in at 4.11pm.
“Emergency services worked together to locate the person who got caught in the fast-moving tide, and bring the casualty to safety.
“Fire crews left the scene at around 5.30pm.
“Fortunately in this instance the casualty was wearing a life jacket and had someone with him to call the emergency services. This incident demonstrates the importance of wearing suitable clothing and having good knowledge of the local area and when carrying out water-based activities.”

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Emergency services, including the RNLI and fire service, attended the scene. Picture: Sussex News and Pictures Photo: Sussex News and Pictures

2. Arundel incident 4.jpg
Emergency services, including the RNLI and fire service, attended the scene. Picture: Sussex News and Pictures Photo: Sussex News and Pictures

3. Arundel incident 2.jpg
Emergency services, including the RNLI and fire service, attended the scene. Picture: Sussex News and Pictures Photo: Sussex News and Pictures

4. Arundel incident 3.jpg
Emergency services, including the RNLI and fire service, attended the scene. Picture: Sussex News and Pictures Photo: Sussex News and Pictures