Reply to the Discussion of “The ‘lost’ islands of Cardigan Bay, Wales, UK: insights into the post-glacial evolution of some Celtic coasts of northwest Europe” by Catherine Delano-Smith, Phil Bradford, and William Shannon

range of conclusions. Whilst prefacing their introduction to sources with a general note of caution, Haslett and Willis (2022) present examples, not in support of any conclusions of their own but as a prerequisite for embarking on the study in providing at the outset a level of reassurance that suggests the islands depicted on the Gough Map merit further consideration. However, Delano-Smith et al. (2022) provide a welcome clarification to the mistake that the Gough Map is not the earliest known map of Great Britain (Haslett and Willis 2022; National Library of Scotland 2022) but rather is more correctly described, for example, as the “earliest known surviving map of Britain drawn on a separate sheet” (DelanoSmith et al. 2017, p. 3) and the “the earliest map to show Britain in recognizable form” (Nurse 2022, p. 50). The possibility that islands once existed in Cardigan Bay, as depicted on the Gough Map, prompted Haslett and Willis (2022) to reconsider Ptolemy’s coordinates as corrected by North (1957). The coordinate for the mouth of the River Teifi (Afon Teifi) at the southern end of Cardigan Bay is near its present-day location. A geomorphological explanation for an unchanged position is possible in that a radiocarbon date of 9539-10 154 cal. BP suggests that the Trawling Grounds bathymetric feature offshore of the river mouth may have been open to marine conditions and possibly a seaway for several thousand years, which may conceivably have been accessible to early seafarers (see fig. 4 of Haslett and Willis 2022). Northward along the coast, however, the next coordinate, for the mouth of the River Ystwyth (Afon Ystwyth), lies some 8 miles (ca. 13 km) west of the present-day location of the river mouth. While fully appreciating the comments of Delano-Smith et al. (2022), the depiction of offshore islands on the Gough Map appears consistent with REPLY