The small boat rocked back and forth in the wind and waves, causing concern.
Tips
grammar
摇摇晃晃 is an AABB reduplicated form from 摇晃 (to sway). AABB reduplication intensifies the vividness or duration of the action/state. It functions adverbially before verbs (摇摇晃晃地走 — to walk staggeringly) or predicatively (走得摇摇晃晃).