A vessel provided with a telescopingly extendable gang plank mounted thereon for movement about a vertical axis. A coupling device provided at the free end of the gang plank is adapted to enclose a vertically directed engagement rod on an offshore pole body and thus connect the ship to the pole body. With tile ship manoeuvred in a certain position the gang plank may be either directed and extended towards tile engagement rod or be manoeuvred while taking its extended position laterally into contact with the engagement rod and subsequently (partially) retracted again.