Boating and marine
General: http://www.marinewa.com.au/
Safety, regulations etc: http://www.transport.wa.gov.au/imarine/15830.asp
Weather: http://www.weatherzone.com.au/marine/wa
Shark safety: http://www.fish.wa.gov.au/Education-and-Partnerships/Shark-Hazard/Shark%20safety/Pages/Shark-safety-FAQ.aspx/
Diving
http://www.ningalooreefdive.com/
http://www.perthdiving.com.au/
Fishing/Fisheries
Department of Fisheries: http://www.fish.wa.gov.au/Pages/Home.aspx
Licence: https://secure.fish.wa.gov.au/fisheries/TCForm.jsp
Rules and regulations: http://www.fish.wa.gov.au/Fishing-and-Aquaculture/Recreational-Fishing/Recreational-Fishing-Rules/Pages/default.aspx
Education/resources
Western Australian Marine Science Institution: http://www.wamsi.org.au/
Oceans institute, University of WA: http://www.oceans.uwa.edu.au/
Atlas of Living Australia: http://www.ala.org.au/
OZCAM (Online Zoological Collections of Australian Museums): http://www.ozcam.org.au/
WA museum http://museum.wa.gov.au/
Fishes of Australia: http://www.fishesofaustralia.net.au/
http://marinewaters.fish.wa.gov.au/
Maritime museum: http://museum.wa.gov.au/museums/maritime