A sunny forecast is not a dive forecast. Wind direction, swell period, tide, runoff and site orientation can make two nearby sites behave very differently.
Forecasts support a decision; they do not replace seeing the site or listening to a local operator who understands its thresholds.
Three views of the same proposed dive
Official forecast
Check the relevant area, issue time and forecast period.
Local briefing
Ask how the conditions apply to the exact site and activity.
On-site observation
Reassess what is happening at the planned entry and exit.
Original YouDive visual discussion guide. Use the article and its sources for context; qualified review is pending.
Put the questions into practice
Open official weather and tide sources and record your questions in the preparation worksheet.
Weather resources & printable worksheet →Separate wind from swell
Wind affects surface chop and boat handling; swell carries energy from elsewhere and can create surge or unsafe entries even on a calm morning. Direction matters because headlands and bays shelter different sectors.
Use tide locally
Tide height and flow matter differently at jetties, channels, caves and open coasts. Some sites require slack water calculated from a local reference rather than a generic city tide table.
- correct tide station
- local lag after high or low water
- entry and exit exposure
- current direction
- boat traffic window
Treat visibility as an outcome
Visibility reflects recent swell, rainfall, plankton, current and bottom type. Yesterday's report may be better evidence than a seasonal average, but it still cannot guarantee the next tide.
Ask what specific forecast value usually changes the operator's site choice. A threshold is more useful than ‘conditions look good’.
Common questions
Which weather forecast is best for diving?
Use official marine forecasts plus local site knowledge. No single app captures every entry, current and visibility factor.
Does offshore wind always mean good shore diving?
No. It may flatten one coast while swell, tide or another exposed section remains unsafe.
Can visibility be forecast accurately?
Only broadly. Recent local reports and the processes affecting the site are more useful than a precise-looking number.
