If you forgot to check the tide table, or you have no signal out on the water, you can still work out tide times in your head. The method is simple. You only need two things: today's high tide time, and how many days have passed since the new or full moon.
The lunar day is roughly 50 minutes longer than ours. So if high tide is at 6:00 today, expect it around 6:50 tomorrow, then 7:40 the day after, and so on.
Once you have added about 12 hours, the clock time comes back around but flips: the high tide that arrived in the morning now arrives at night. That cycle repeats roughly every two weeks.
Most days bring two highs and two lows within 24 hours and 50 minutes, with roughly 12 hours and 25 minutes between high and high. If high tide is at 6:00, the second high lands near 6:25 in the evening.
This one tells you how much water has risen at any point between low and high, which is exactly what you need when deciding whether a shallow channel is passable.
Split the total range between low and high into six parts. In the first hour after low water the level rises one part, in the second hour two parts, in the third three parts, then three, then two, then one.
The practical takeaway: the water moves hardest in the middle of the cycle. That strong current is both your best fishing window and your biggest safety concern.
Official tables are tied to reference stations. In Kuwait the most useful are Shuwaikh and Shuaiba. If you are working the northern side of the bay, use Shuwaikh. If you launch further south, use Shuaiba.
If you are somewhere between the two, split the difference and treat it as an estimate, not a precise figure.
Do not lean on hand calculation alone. Use it as a fast cross-check. The B7R app gives you tide times for Shuwaikh and Shuaiba directly, alongside sea state and the seasons guide, so you can compare your own estimate against the table before you launch.
Then log it in the fishing log: the tide time you actually fished, and how far your estimate was from reality. After a few weeks your own predictions get noticeably sharp.
First, forgetting that strong wind shifts both the height and the timing of the tide. Second, mixing up high tide and low tide when reading a table. Third, ignoring the daily 50-minute drift, which adds up to several hours within a week.
Make it a habit: check the table, run the quick estimate, compare the two, then go. It becomes automatic fast.
Download the B7R app free on Google Play: b7r on Google Play