The cannon at Zonchio were too weak to sink large ships reliably. Enough accumulated damage might eventually sink one, but that was unlikely. An artillery duel could still break up an opposing formation and give Venice's large carracks an opportunity to attack. That opportunity remained conditional on the Venetian fleet advancing, and it would face Ottoman heavy sailing ships whose precise positions are uncertain.
Notable Point · 54:14-55:29
How early cannon could disrupt a fleet formation
At Zonchio, cannon were unlikely to sink large ships, but an artillery duel could disrupt formations and create an opening for Venice's heavy sailing ships.