11. Neap tides are the lowest high tides and highest low tides, marking the first and third quarters .)12. Neap tides , on the other hand, are those in which the water rises and falls the least.13. At Philips Point spring tides rise 25 to 30 feet, and neap tides from 16 to 20 feet. 14. Spawning takes place between June and October, at night at two-weekly intervals coinciding with neap tides . 15. Because the tidal speed doubles, eight times more tidal power can be produced at spring tides than at neap tides . 16. The semimonthly markings created by spring and neap tides are prominent and easier to identify and count than the daily tidal marks. 17. At neap tides , this interaction is less pronounced, without tides surges would occur more randomly, approximately every 12 hours. 18. This latter approach had caused problems at spring tides, although on neap tides Giant's Grave still had to be used. 19. An arrow on the tidal chart indicates the direction and the average flow speed ( usually in knots ) for spring and neap tides . 20. When the sun is at right angles to the moon, the effects are partially cancelled, producing the small tides called neap tides .
