The Bureau of Meteorology (BOM) Australia is the best place to check the weather.
The general forecast for Sydney from the BOM
Sydney Harbour Forecast
Sydney Closed Waters forecast from the BOM.
Note that sometimes the Metropolitan forecast seems to conflict with the Coastal Waters forecast - different departments in the bureau can give different forecasts!
Marine Wind Forecast for Sydney
A graphical representation of the wind forecast from the BOM.
Latest Sydney Observations
Current wind speed and direction from automatic weather stations from the BOM. Fort Denison AWS gives a good indication of Sydney Harbour current conditions. You can also click on the link for each AWS to see data from past observations and get an idea of the trend or see how they got today's forecast completely wrong!
Weather Radar for Sydney
The BOM weather radar which covers a radius of 128 km around Sydney. This is a link to the radar located at Terry Hills. The Doppler Wind link on that page will show you wind speed. Lots of neat features!
Tide predictions for Sydney (Fort Denison).
3 Day Tide Graph
A graphical presentation showing tides, sunrise, sunset, moonrise from Manly Hydraulics Laboratory.
7 Day Wind & Wave Forecast for Sydney
From seabreeze.com.au a graphical wind & wave forecast.
Sydney Sea Surface Temperatures
Offshore Sydney sea surface temperatures from Manly Hydraulic Laboratory
NSW Offshore Wave Heights and Sea Surface Temperatures
From Manly Hydraulic Laboratory. "Hsig" on the wave height graph is the "significant height" - average height of the waves which comprise the highest 33% of waves in a given sample period.
Netatmo Weather Map
Netatmo is a personal weather station you can purchase - you get an indoor and outdoor unit and you view the readings via a smart phone app. Owners can make their data public. This map shows these personal weather station readings all around the world. There are plenty in Sydney and most suburbs seem to have some. The accuracy of readings depends on how well the owner has installed the unit (e.g. out of direct sunlight, off the ground etc) and some seem to have the humidity stuck on 100%. It's pretty neat nevertheless.
A good weather portal with pages for wind, rain, sunrise, tides, swell etc.
Sydney Morning Herald weather page
A good general weather page .
Compute Sunrise/Sunset Times
via Geoscience Australia website
(You will need to select a location -Sydney - from the top of the page and then chose the other options you require before clicking on 'Compute'. Alternativel enter Sydney's location Lat=-33051' Long=+151007')
Weather for Sailors
This is a really neat site that gives weather conditions recorded by ships at sea and includes a ship tracker that gives the location of ships around the world.
Shipping Arrivals and Departures
Port Operations website gives you the shipping schedule for Sydney Harbour and Port Botany.
Under the Weather
Pubs of Balmain Peninsula
OK, when the weather's bad and you can't go kayaking perhaps you can have fun exploring Balmain. For lunch I'd recommend either the Royal Oak or Dry Dock Hotels. There's also no shortage of coffee shops and restaurants. Balmain markets are on each Saturday just across the road from the London Hotel.
Waterfront Pubs, Clubs, Cafes
Here's a map of various waterfront cafes, pubs and clubs around Sydney.