Complex sentence: On lifeguard (aircrew rescue) duty in support of carrier air strikes on Saipan, "Seahorse" next sighted and sank the Japanese submarine "I-174", one of the few submarine attacks on another submarine in World War Two.
Split into simpler sentences: On lifeguard (aircrew rescue) duty in support of carrier air strikes on Saipan, "Seahorse" next sighted and sank the Japanese submarine I-174. This was one of the few submarine attacks on another submarine in World War Two.