These tables show the estimated clearance under the second span of the bridge (from the eastern side) for various heights above the waterline. These are worst case figures where it is assumed that you arrived on a rising tide and had to wait for it to peak and then fall. The tables are calculated from 1st Jan 2000 to 31st Dec 2000. I have also checked tides up until 2037 and there is no significant difference. The peak tides occur in January and June, so discounting the off season halves the affected days.
1893 is estimated so stand 1.97m metres high to the top of the forward navigation light.
Times are adjusted for daylight saving (excluding new rules for the Olympics) except for the raw data.