On the inner parts of this ground, particularly, the gill-net fleet operates extensively, mainly in the full and spring, on northwest Jeffreys 8 to 12 miles E. and SE. from Thacher Island, where the bottom is sand and rocks. Other gill-netting grounds are 8 to 15 miles NE. by E. from Thacher Island in 22 fathoms on a hard bottom of mud and mixed material of sand and gravel. The Cove of Jeffreys, NE. by E. 12 to 15 miles from Thacher Island, is a favorite haddock ground in the spring (April 20 to May 15) in 45 to 70 or even 80 fathoms, although gill nets are not often fished in more than 50 fathoms because of the, weight of the nets in the deeper water. In the spring (in April and May), the haddock come in on Scantum, 10 miles NNE. from Thacher Island between Jeffreys Ledge and the Isle of Shoals, on a broken bottom of rocks and blue clay in 55 to 70 fathoms.
Off Newburyport and N. and SW. of the Isle of Shoals are gill-netting grounds that are much used. Trawling and netting are carried on, beginning in 40 fathoms in February and March and working off to 70 fathoms off Salisbury Bench in May. Cod are on this ground about two weeks in October and in February and March are found in abundance off Boars Head. Hake are present here all the fall and are found all along the southeast side of these grounds in depths of 45 to 60 fathoms. A certain amount of halibut may be taken in most years at various points on a bottom of hard gravel in spring and early summer in 35 to 65 fathoms. In most years a large amount of mackerel is taken on Jeffreys, notably so in 1925. Herring, also, are usually abundant here in "herring years".
The Shoal Ground, stretching easterly from Thacher Island, has depths from 20 to 30 fathoms over a bottom of sand and gravel. This area is about 15 miles long by 5 miles wide and is an important pollock ground in their spawning time as well as a good fall cod-fishing ground. It is about 12 miles E. by N. from Thacher Island to its center and 21 miles SE. by S. from the Isle of Shoals. Flounder draggers also operate here on the shoal ground and all around Thacher Island but mostly to eastward & southeastward.
Tillies Bank. [13] This bears E & S from Eastern Point Light just dropping Thacher Island Light, then 3 miles farther for best fishing: and E. by S. ½ S. from Thacher Island, Cape Ann, from which the shoal on the center of the ground is distant 18 miles. This is a small rocky spot with depths of from 25 to 28 fathoms, outside of which the water deepens to 40 fathoms over a considerable area. The length of the entire ground is about 10 miles in an E. and W. direction and the width about 5 miles. At the edge it falls off rapidly to depths of 50 to 60 fathoms before reaching the mud at still greater depths but an area of shoal water connects this ground with West Jeffreys. The bottom is rocky and rough over the greater part of the bank. Tillies was formerly regarded as one of the best fishing grounds off Cape Ann and is still resorted to for cod and haddock in the spring and fall; for hake in the spring, summer, and fall, and for pollock in the spring and fall. The fishing is mainly by trawling, with the gillnetters operating on the shoal grounds in less than 50 fathoms.