Neap tides occur when the sun, earth and moon form a right angle and the gravitational pull of the sun counteracts the pull of the moon. The tide occurs when the difference between high and low tide is least. Neap tide comes around twice a month, in the first and third quarters of the moon. In comparison, a Spring tide occurs when the difference between high and low tide is greatest. Similarly, Spring tides occur twice a month, approximately at the full and new moon. Spring tides occur when the sun and moon are directly in line with the earth and their gravitational pulls reinforce each other.
Diving during a Neap tide could be advantageous as the tidal flush is reduced and although slack tide duration will not be affected, the increase of surge or water flow will be reduced when compared to a Spring tide. Another benefit of diving during a Neap tide is that your target dive site will be shallower.
Here’s the link to the 2018 BSAC Dive Planner to help you plan your diving.