These are the names found on the Ordnance Survey Maps and Hydrographic Charts pertaining to the Isles of Scilly. For general interest only, refer to an appropriate chart.
The western approach to the Isles of Scilly is 'Broad Sound'. In the area SV 86000, 10500 'The Broad Sound 'splits into two. To the northwest is the Northwest Passage and the Broad Sound eventually becomes 'The St Mary's Road'. Just prior to this point in the general area of SV 88300, 11700 The St Mary's Road which passes between northwest St Mary's and southeast Samson / Tresco intersects with St Mary's Sound which continues southeast between southwest St Mary's and Gugh.
In the area around the Crow Rock, SV 91000, 13200, The Road passage becomes Crow Sound continuing in an easterly direction away from the islands.
At SV 91500, 13300 there is a north passage which will take you north between west St Martin's and the island of Tešn (Tešn Sound).
At SV 85100, 12300 on the North West Passage there is a 90 degree turn to the northeast, between north Samson and south Bryher heading to the Tresco Flats. Here with careful navigation a passage between Bryher and Tresco is achieved returning to the northwest direction.
Crebawethan Neck - Between south of Great Crebawethan and the rocks northwest of Jacky's Rock.
Santaperry Neck - Between Silver Carn and north Rosevear.
Rosevear Neck - Between southern Rosevear and Rosevean.
Broad Neck - Between Rosevean / Daisy and the west of the Rags .
Shoal Neck 1 - Between the east of the Rags and Gorregan.
Gorregan Neck - Between Gorregan and Melledgan.
Muncoy Neck - Between Muncoy Ledges / Melledgan and Isinrank / Brothers (Rocks).
Shoal Neck 2 - Between Isinrank / Brothers (Rocks) and the The Brow.
Hellweathers Neck - Between Hellweathers and the The Brow / Menrounds.
Annet Neck - Between the south tip of Annet and and the Old Woman's House.
Smith Sound - Between west St Agnes and Annet / Rocks south of Annet.
St Mary's Sound - Between east of Gugh and southeast St Mary's.
Northern Area (West of Samson & Bryher)
Garden of Maiden Bower - Between south Maiden Bower / Murr Rock and northwest Seal Rock.
Seal Rock Neck - Between southeast Seal Rock and west Illiswilgig.
Castle Bryher Neck - Between east Illiswilgig and west of Castle Bryher.
Outer Neck of Gerwick - Between east Castle Bryher / Buzza Rock and southwest of the Gerwick rocks.
Inner Neck of Gerwick - Runs on the northeast of the Gerwick rocks and the southwest of Bryher.
Little Neck - Can be found to the north of Scilly Rock, south of Sharp Rock.
Gweal Neck - Between Gweal Hill, Bryher and Gweal island.
Popplestone Neck - Takes you into Popplestone Bay, west Bryher.
New Grimsby Sound - Between north Tresco and Shipman Head, north-east Shipman Head, Bryher.
New Grimsby Harbour - Between north-east Bryher & north-west Tresco.
Old Grimsby Sound - Northeast Tresco.
Beef Neck - Northeast Northwethel and southwest St Helen's island.
St Helen's Gap - Between southeast St Helen's and northwest Tešn.
St Helen's Pool - North-east Tresco. Between St Helen's, Tešn and Northwethel
Neck of the Pool - West St Martin's, south of Lower Town.
Great English Island Neck - Southeast St Martin's, between English Island and Great Ganilly (Eastern Isles)
Little English Island Neck - South Gun Hill St Martin's, east Higher Town bay
Tešn Sound - Between Tešn and west St Martin's.
Little Ganilly Neck - Between Little Ganilly and Little Arthur.
Arthur's Neck - Between the east of the Ganinicks and the west of the Arthurs.
Menawethan Neck - Between south Great Innisvouls and north Menawethen.
Great English Island Neck - Between the southeast shore of St Martin's and the small islet of Nornour, Eastern Isles.