We want to travel the full route of the Coastliner 840 bus from Leeds, where will vacate a hotel room, to Whitby, where we will get a hotel room. We also would like a couple of nights in Scarborough, between Leeds and Whitby. I understand there's a split in the route, and going to Scarborough will have us on the Coastliner 843 bus. How best to structure a multiday trip so that we get the full 840 experience, but also see Scarborough and have time to take the lunch journey on the North Yorkshire Moors Railway?
First logistical advice. Leeds Bus Station now charges for it's toilets. Since that started I now use the ones in the adjacent market hall, where there are also some very good food options to have breakfast (or lunch depending on the time of day) before the journey,
Take the 840 all the way through, then on your Whitby day take the hourly X93 up the coast- journey time 1 hour, first at 0746, then 50 past each hour.
Then on the way back (to York?) the 843. Having done the York to Malton stretch on the 840 I would either change to train at Malton, or use the villages/Castle Howard route 81 from Malton to York- https://passenger-line-assets.s3.eu-west-1.amazonaws.com/eyms/EY/81-timetable-20251120-4f5e48bb.pdf
If you have time the onward routes from Whitby to Middlesbrough are also pretty scenic- it is well worth doing a circular X93 route one way (hourly- 1 hour journey), X4 the other (every 30 minutes- 2 hour journey)- https://www.arrivabus.co.uk/north-east
I actually strongly suggest a stop at Malton on the way to Scarborough, both for sightseeing, and also as a personal needs break on the long journey.