There is no negotiating with the weather. It can change at any time, forcing you to change course or ride it out. Checking weather forecasts at least gives you the best odds of having a pleasant cruise instead of a white-knuckle ride! You can get marine weather forecasts by radio, TV, newspapers, VHF radio (below) or Telephone (free and paid), and of course - the Internet.
MAFOR Code - world standard numeric code for marine forecasts
With a small mobile phone, we can look up most weather information, but looking up at the clouds still provides useful information when you're out on the water. (Cloud Cover)
If jet trails disappear quicky, the air is dry and weather is stable. If the trails remain and spread out, prepare for a change in the weather in about 24 hours.
When you see high hair-like strands of Cirrus clouds forming into a thin veil, expect active weather in the next 18 to 24 hours.
When puffy Cumulus clouds start to mushroom upwards, watch for thunderhead formation (Cumulonimbus clouds), which can happen in helf an hour. An anvil shape forms as it reaches high altitude winds, which flattens the top of the cloud. Thunderheads normally move from south-west to north-east. The base turns darker as heavy rain, gusty winds and lightning begin, all dangerous for boating. If you notice distant thunder or lightning south-west of you, don't hesitate to get to safety.