 Complete the following phrase:  Another minelaying operation took place on 2526 June; this time, Thetis escorted minelayers that laid a field in the Sea of Åland. Thetis again came under torpedo attack from an unknown submarine, though she was not hit. On 19 July, Thetis was based in Windau for a planned attack on the Gulf of Riga by elements of the High Seas Fleet. In August, Thetis was assigned to the fleet that was to 