Fifteen members of the rescue team had been planning to use specialist equipment to get across the mud and reach the whales. However, due to the inaccurate location reports, they could not find them on Monday.
Access on Monday evening was believed to be by Harty Ferry Road, with a walk of three-quarters of a mile (1.2km) across the mud.
Rescuers described the access conditions as “shocking”.
Pontoons were being brought from London to help get 4×4 vehicles with equipment across the flats.
Members of the UK Cetacean Stranding’s Investigation Programme, which handles all reports of stranded whales, will examine the site.
The organisation attends whale strandings so it can carry out post-mortems to determine whether they occurred naturally or have been driven by human activity.
