during which phases of the moon are the high tides and low tides at extremes
Tidal range The most extreme tidal range occurs during spring tides, when the gravitational forces of both the Sun and Moon are aligned (syzygy), reinforcing each other in the same direction ([new moon]]) or in opposite directions (full moon). During neap tides, when the Moon and Sun's gravitational force vectors act in quadrature (making a right angle to the Earth's orbit), the difference between high and low tides is smaller. Neap tides occur during the first and last quarters of the moon's phases. The largest annual tidal range can be expected around the time of the equinox, if coincidental with a spring tide.
Bay of Fundy The Bay of Fundy is known for having the highest tidal range in the world. Rivaled by Ungava Bay in northern Quebec, King Sound in Western Australia, Gulf of Khambhat in India, and the Severn Estuary in the UK, it has one of the highest vertical tidal ranges in the world. The Guinness Book of World Records (1975) declared that Burntcoat Head, Nova Scotia has the highest tides in the world: