The monument comprises a stretch of inland waterway forming part of the Crinal Canal running from the summit reach at Cairnbaan, immediately E of lock number 9 to the sea-lock (lock number 1) at Ardrishaig. The canal was designed by the eminent Scots engineer John Rennie and built c 1794-1809 as a ship canal linking the two sea lochs, Crinan and Gilp.
The area proposed to be scheduled includes all that part of the canal in water together with all of the towpath running along the N, NE and E banks and a narrow strip of ground to either side of the canal and towpath. The following canal structures are also included in the proposed scheduled area:
 masonry feeder arch W of lock number 8;
 lock number 8 at Cairnbaan;
 lock number 7 at Cairnbaan;
 lock number 6 at Cairnbaan;
 metal swing-bridge W of lock number 5 at Cairnbaan;
 lock number 5 at Cairnbaan;
 three-arch masonry overflow at Craig Glass Burn;
 masonry culvert carrying unnamed burn opposite Badden Farm under the canal;
 metal swing-bridge (Oakfield Bridge), W of Lochgilphead;
 masonry engine house containing automatic water waster N of Hazelburn Cottage, N of Ardrishaig;
 masonry culvert carrying unnamed burn beside Hazelburn Cottage under the canal;
 four-arch masonry overflow opposite Towpath Cottage, Ardrishaig;
 masonry culvert carrying the Kilduskland Burn, Ardrishaig, under the canal;
 stop-lock beside Glenfyne Park, Ardrishaig;
 lock number 4 at Ardrishaig;
 metal swing-bridge at lock number 4;
 lock number 3 at Ardrishaig;
 lock number 2 at Ardrishaig;
 metal swing-bridge carrying the A83 over the canal at Ardrishaig;
 concrete sea-lock (lock number 1) at Ardrishaig, built to replace  below;
 remains of original sea-lock at Ardrishaig.
The area proposed to be scheduled excludes all modern fixed and floating concrete, metal and timber jetties/moorings; all modern fences, gates, posts and markers; all modern road surfaces and modern canal buildings, but includes an area to either side of the canal and towpath in which features associated with its construction and use may survive, as marked in red on the attached map.