You will be like one sleeping on the high seas, lying on top of the rigging. (NIV)
Yes, you will be [as unsteady] as he who lies down in the midst of the sea, and [as open to disaster] as he who lies upon the top of a mast. (AMP)
Yea, thou shalt be as he that lieth down in the midst of the sea, or as he that lieth upon the top of a mast. (KJV)