Eastbourne lifeboat was launched following multiple reports of red flares in the skies on Sunday (June 2).
The inshore lifeboat (ILB) and its crew were tasked by HM Coastguard to investigate the signal, spotted in the Cooden area.
When on scene they encountered a small tender with one person aboard, said the RNLI.
A spokesperson said, “The individual had apparently set out from Rye in company with another small vessel but had lost sight of his companion and became concerned.”
After investigations by the Coastguard it was established the other vessel had turned back due to the adverse weather conditions and was safe.
The ILB escorted the remaining tender into the safety of Sovereign Harbour.