 After a return to Pola on 12 July, the U-boat underwent extensive repairs that kept her out of action for the next nine months.On 16 March 1918, the newly refitted boat sailed from Pola to Cattaro, departing that port for another Mediterranean tour on 25 March.Near Valona the next day, an Italian destroyer attempted to ram "U-29", scraping one of her propellers against "U-29"s conning tower.