I'd expect the inshore high tide to be later, not earler, but that probably just shows how much I know about it. But the effect isn't as dramatic as it sounds. Assume the shape of the tides to be approximately sinusoidal, high (and low) tide is around the turning point, where it is changing slowest. 40 minutes difference in about 24 hours 25 minutes, that's 0.027 cycles, or 10 degrees. Cosine of 10 degrees is 0.98, so the difference in tide height is 0.02. The tidal range at Whitby might be 10 metres, so the difference in water level between shore and buoy is 200mm in 3/4 mile, a gradient of 1 in 6000. That's less than the gradient of a canal, so there's no great current caused.