We are continuous cruisers and do use Tesco’s for canal-side deliveries. We use postcodes, of the nearest houses, pub addresses, bridge locations, again with postcodes. Always putting a note that we are on the canal, or will meet them in the car park. The delivery drivers have always been very helpful, and polite. I have had problems with quality, or wrong product being picked, but a phone call and the items are credited. One driver told me that it was best to allow substitutes as when they are delivered these items are pointed out first, and they can be rejected. Tesco say in their blurb that the longest shelf life available will be sent, and I have not had any problem with the likes of eggs or bread.
Have only ever used Tesco’s so cannot speak of other supermarket deliveries, but would and do recommend them.