To work as a skipper in Australia
AMSA :: Australian Maritime Safety Authority
for the up to date info.
You will find that your overseas commercial
sea time is valid for an Oz ticket and some of your recreational time will be valid for the entry level commercial tickets.
You'll also find that Australia is a lot stricter than most countries with these tickets as it takes a lot longer to get an equivalent sized ticket in oz than overseas. For example a commercial skipper in oz for a vessel less than 24metres needs far more seatime than the equivelant in the UK or America however the oz ticket is not pax limited so you could be skippering a 200pax ferry
with that ticket.
When I did my skippers ticket (in freo) we happened to have a young american skipper in the class (who had the US 200tonne ticket). His impression was that the education level and overall standard was higher in Oz..
This has changed recently with a national system (under AMSA) with less requirements for sea service
etc but the overall systems standards are higher than foreign small commercial vessel certifications.