The RSPB have a high tide event on the 21st of February. The tide forecast is 10.1m. Is this the first of the 10 metre tides of that week. If it is 10metres or less the day before is it worth going on the 20th? If its 10.1 metre plus on 22nd ...could that day be better? Could there be even higher tides in about 4 weeks?