krstariti

1. (of sailing) to cruise; to sail around
   Leto provodimo krstareći Jadranom. — We spend the summer cruising the Adriatic.
   Turisti krstare Dunavom od Beča do Beograda. — Tourists cruise the Danube from Vienna to Belgrade.
2. (of patrols, warships) to patrol
   Ratni brodovi krstare obalom. — Warships are patrolling the coast.
   Policijska kola cele noći krstare ulicama. — Police cars patrol the streets all night.
3. to cruise around; to roam
   Subotom uveče krstarimo gradom bez cilja. — On Saturday nights we cruise around town aimlessly.
   Satima krstari internetom. — He spends hours surfing the internet.

The area covered is usually in the instrumental without a preposition: krstariti Jadranom, ulicama.