Hi Sigge: The answer is a definite yes, and that is what the first part of the Mariner’s Weather Handbook is all about…using the indicators around you (sky, wind direction and speed, sea state and barometer) to figure out what is going on. A critical part of this is a detailed written weather log, which will give you the all-important trends. Most of the 200,000+ miles we’ve sailed have been without any fancy weather gear, and these onboard basic forecasting techniques have done well for us. Having said all of the above, I feel strongly that the ability to receive (and understand) weather faxes help enormously in both pasage time, reducing boat maintenance, and safety. If I had to make a decision between a fax and an inverter to make AC power, I’d take the fax. On the other hand, if the decision was between a fax or going cruising a year earlier, I’d probably go sooner. Hope this helps.