One possible source is a Scandinavian word meaning to 'leap up'. Another possibility is that it is related to the natural feature of a spring - which is a place where water wells up from the earth. The second largest tides in the world occur at Avonmouth in the Bristol Channel where the average spring range is 12.3 m. A day or two after the full or new moon nearest to the equinoxes. The spring equinox is usually the 21st March, and the autumn equinox, the 23rd September.
Some years have tides that are notably higher than other years.
1997 was a significant year, as will be the year 2015. For really favourable conditions - you will have to wait around until the year 3182. Even then, the tides may only be 1 or 2 cm higher than in 1997. The nearest approach of Venus to earth is still more than 100 times further away than the moon. Hence the tidal force is approximately 0.000054 times that of the moon.