Rip currents are keeping lifeguards busy at the Jersey Shore. Three men swimming off Lavallette were rescued by lifeguards Saturday after they became caught in a dangerous undertow. The men initially were spotted shortly before noon by two police officers who were patrolling in the area. The three swimmers were all taken to a hospital for observation, but were later released. Water rescues were reported Saturday at beaches in Sea Bright and Seaside Heights, where lifeguards swam out to rescue distressed swimmers. But no serious injuries were reported. Authorities were warning swimmers about the rip currents on Sunday, as large crows packed Jersey Shore beaches. Lifeguards made some additional rescues on Sunday afternoon, but no injuries were reported.