How to Use this Atlas

This atlas is meant to be used in conjunction with the current annual Tide Tables for Halifax Harbour (e.g. [2]). The general pattern can be obtained directly from one of the diagrams. Two sets of figures are given; the first set (Figures 1 - 12) covers the whole Harbour, the second set (Figures 13 - 24) covers the central part in greater detail. The strength of the current is determined by comparing the length of the current arrow with the 5 cm-1current scale vector shown. The current magnitudes are derived assuming an M2 tidal range of 1.24 m; however, Tide Tables indicate the tidal range can be as high as 2.1 metres, these should be further scaled for more accurate predictions.

1. Find the tidal diagram appropriate to your time relative to the tides in the Tide Tables. (Remember that the times in the Tide Tables are always local standard time never daylight saving.)
2. Determine the range (in metres) of the tide that includes the time of interest by subtracting the low from the high tide.
3. The scale factor for the currents is range/1.24.
4. In the special case where the time is exactly at high or low tide (see the second example) the range should be taken from the rising or falling tide that immediately precedes that time.