Sydney Harbour, passing Garden Island. 21 May 2017.
Vessel at 33°51'24.16" S 151°13'51.91" E

Marine Traffic data:
IMO: 1012555
MMSI: 503018980
Call Sign: VJN4752
Flag: Australia [AU]
AIS Vessel Type: Pleasure Craft
Gross Tonnage: 250
Deadweight: -
Length Overall x Breadth Extreme: 44m × 10m
Year Built: 2014

Data from http://www.superyachttimes.com/yachts/details/4972
Imo: 1012555
Call sign: SYT#: Y04972, Flag: Cayman Islands
Length Overall (m): 44.10 Length Overall (ft): 144.69
Shipyard: Alloy Yachts Year: 2014
Hull: AY54 Status: Completed
Port: Auckland Country: New Zealand
Naval Architect: Alloy Yachts
Exterior Designer: Sam Sorgiovanni Designs P/L
Interior Designer: Redman Whiteley Dixon Ltd.
Hull Material: Aluminium Superstructure: Aluminium
Gross Tonnage: 499
Class: Lloyds Register