One number decides more trips than any other: wave height. It looks simple on a forecast, but what it means for you depends on the kind of waves, the size of your boat and where you plan to be. Read it properly and you stop gambling with your morning.
Wave height is measured from trough to crest, and forecasts usually give an average with a range. A half-metre forecast does not mean every wave is half a metre; some will be taller. It also describes open water, not the confused water at a channel mouth or over a shallow bank.
So treat the number as a starting point, not a verdict. Two feet of long, orderly swell is a completely different day from two feet of short chop, even though the forecast reads the same.
Waves also arrive in sets, not one at a time: a group above the average, then a calmer gap, then another group. Good boat handling means reading the set and picking your crossing, not punching through the largest one.
Swell is long, well spaced and carries energy from distant weather. It can be big but predictable, and you can time your crossing. Chop is short, steep and local, generated by the wind blowing right now. It stacks up fast, throws spray and punishes small hulls.
Watch the interval, not only the height. Widely spaced swell gives you a longer, calmer gap to cross; tightly packed chop gives you none.
Wind builds the short waves, and a shamal from the north can lift the sea quickly, especially on exposed ground. Wind running against the current makes waves steeper and shorter, while wind with the current tends to flatten them.
Tide matters too. On a low tide the waves hit shallower bottom and stand up, so the same wind feels worse. Compare the morning and afternoon forecast rather than trusting a single reading, and note that the calmest hour is often when the wind is changing direction.
There is no universal safe number, because boats and skippers differ. Work out your limit before you need it:
Write the number down and tell whoever is fishing with you, so the call is not an argument at the ramp before dawn. A limit decided in calm weather is a better limit than one argued out in wind.
Cancel if the forecast is above your limit at all, if it is trending upward through the day, if a warning is out, or if your gut says no while the boat is still on the trailer. Calling off a trip costs you one morning; the other option can cost a lot more.
Before you hitch up, check sea state and the tide times for Shuwaikh and Shuaiba ports in the B7R app, then compare them with your own limit. B7R app is free on Google Play: https://play.google.com/store/apps/details?id=com.q8dm.b7r