Anti-migrant activist Daniel Thomas, known as Danny Tommo, has pleaded not guilty to charges of criminal damage and failing to disclose the PIN to his phone.
The 37-year-old appeared at Basingstoke Magistrates' Court via videolink. He was arrested after a video appeared to show him slashing a dinghy in the English Channel, which had an emergency responder on board.
Hampshire Police had previously stated that an arrest was made after a "boat that had an emergency responder on board" was damaged in the Channel on Tuesday. Supporters, including far-right activist Stephen Yaxley-Lennon, gathered outside the court and a police investigation centre.