The Galloway coast was used as a landing place for vessels smuggling goods [tobacco and spirits, mainly] into Scotland. The advantages were the proximity of the Isle of Man (then a sort of free port) and the remoteness of some of the beaches.
One base for smugglers was Clone - a beach NW of Port William on the East side of Luce Bay. The farmhouse [Clone Farm] there has been discovered to have secret hiding places built in. In 1777 a large quantity of tea, brandy and tobacco was recovered from the farm.
The revenue cutter for SW Scotland was based at Millport on Great Cumbrae. In 1778, a larger vessel was acquired - the Cumbrae Cutter, later called Royal George. She was commanded by James Crawford and had 16 guns, was around 250 tons, and had a crew of 60.
Painting based on a contemporary sketch of the revenue cutter Royal
George [from North Ayrshire Council]
Newspaper reports of an attempt by the revenue cutter to dissuade smugglers:
From Cumberland Pacquet, and Ware's Whitehaven Advertiser - Tuesday 02 October 1781
  Tuesday se'nnight, the Cambrays [sic: Cumbrae] cutter,
revenue cruizer belonging to Glasgow, commanded by Mr. James Crawford,
fell in with a large smuggling cutter, mounting 22 guns, and full of
men, discharging cargo at the Clone in Glenluce Bay [sic: Luce Bay],
on the coast of Galloway in Scotland, at eleven o'clock in the
morning: Fifty-two carts were then employed on the shore. A running
fight commenced, and continued till both vessels were near the Calf of
Mann[sic], when the Cambrays cutter lost her main haulyards, and was
unfortunately very much damaged in other parts of his rigging, which
obliged him to desist from the engagement; but not till the other was
beginning to shear off, and Capt. Crawford was unable to pursue; he
stood down the North Channel, and the smuggler to the Southward.
  Further accounts say, that she returned that evening, and discharged
the remainder of her loading.
  Last Saturday, a large smuggling cutter, mounting 22 nine pounders,
and a great number of men on board, was laying in Laxey bay, on the
coast of the Isle of Man, where she had also been the four preceding
days, discharging her cargo into sloops and small boats, supposed to
be intended for Scotland, and that this place for unloading had been
chosen as more secure than nearer home, from whence one had been
chased a few days before by Capt. Crawford.
This smuggling vessel was reported as wrecked a few weeks later, inbound from Gothenburg in Sweden with a valuable cargo. However, later reports cast doubt on this.
From Newcastle Courant - Saturday 24 November 1781
  Tuesday se'nnight, a large smuggling cutter, mounting 22 guns,
called the Pitt, belonging to the Clone, in Galloway, struck on the
Maiden Rocks near Larne, and was lost. The owner, a Mr Thomas
Morrinson [sic, possibly Thomas Allason, or William Morrison] of the Clone, was drowned, as were
also the Captain, and 37 of the crew; the remainder, viz. 18, took to
the long boat, which was driven with the wind to Knocknagony [sic:
Knockagoney, NW of Belfast, near City Airport], within three miles of
Belfast, where they got on shore. Her cargo is estimated at
£40,000.
Another report, Leeds Intelligencer - Tuesday 04 December 1781
  We hear from Belfast that a large smuggling cutter of 22 guns, from
Gothenburgh to a port in Scotland, split on a rock near Larne, and that
17 of the crew perished - 32 were saved. The prime cost of her cargo was
£40,000.
A differing report: from Dublin Evening Post - Tuesday 13 November 1781
  Extract of a letter from Belfast. It is now pretty generally believed
that no vessel was wrecked lately off Larne, reported here very strongly
for some days past, but that the 32 men who were driven ashore near
Knocknagony-hill, belonged to a privateer that fought Captain Crawford's
Revenue Cruizer off the Isle of Man some time ago, and who, it is supposed, was
lying off the harbour's mouth on Tuesday last, and sent in their long boat
for the purpose of cutting out the Success, Hugh Henderson, then lying
with a most valuable cargo of linen, waiting for a wind in Carmoyle. - The gale of
wind coming on, obliged them to run for safety in shore, where they
landed, and afterwards dispersed through the country. The captain of a
press-gang in Belfast went in pursuit of the body, but was not able to
come up with them.
[as there is no record of a member of the "Clone Smuggling Company" being
lost in 1781, this latter account is plausible].
Current situation   Wreckage now lies badly broken up on the north side of the Allen Rock (of the Maidens) in 15m of water. It can be dived during neap tides, however, is best dived at slack tide half an hour each side of high water Belfast. This was thought to be the remains of the "Smuggling Cutter", but that seems unlikely, since she was later reported not to have been wrecked on the Maidens.
More evidence of smuggling to Clone:
From Leeds Intelligencer - Tuesday 18 February 1783:
  A letter from Air of the 29th ult. has the following: "Last
night and the preceding, a cutter about 200 tons burthen, mounting 20
nine pounders, navigated with 75 men, chiefly English, Irish, and Scotch
outlawed smugglers, landed at the Clone in Glenluce Bay, shire of
Galloway, 600 anchors [or anker, circa 38 litres] of brandy and gin, and
300 boxes of tea, from Zealand [Netherlands]". The duties due to the
crown on this cargo, if regularly imported, amount to £7000
sterling and upwards. This is the sixth cargo privately imported by the
same company, on the different parts of this coast, since March last,
whereby the revenue has been defrauded of £42,000. and this in
eleven months. These illicit importers have by their great success
become so formidable in the country, that they can raise, on a short
notice, three or four hundred horses and men, many of whom are armed
with bludgeons and clubs, so that the officers and foot soldiers
stationed here are not able to cope with them; and unless a corps of
dragoons or light-horse were appointed on this coast, to assist the
revenue officers, a stop cannot be put to these daring adventurers.
Cumberland Pacquet, and Ware's Whitehaven Advertiser - Tuesday 14
October 1783:
On Wednesday se'nnight, a smart engagement commenced
betwixt Capt. Gellie, of the Prince of Wales, Excise yacht, [cutter,
127 tons burden, 16 carriage guns, 6 and 12 pounders, 50 men] and a
smuggling cutter of equal force, off the Mull of Galloway; the action
lasted upwards of an hour, when Gellie was obliged to sheer off with
much damage, having received a shot between wind and water, another
through his cabin, and several in his rigging, with four feet water in
the hold. Next morning his hands refused to renew the engagement,
although the smuggler lay too for that purpose. We hear that most of
the cargo is landed at the Mull, but very little of it is yet got off.
Leeds Intelligencer - Tuesday 20 January 1784
On the 28th and 29th of December last, two large armed
cutters, mounting twenty-two guns, six and nine pounders each, one of
them called the Thunderer, (who engaged Capt. Gelly near the Isle of
Mann the first of October last, and beat him off in the Prince of Wales
revenue cutter, stationed in Clyde) landed at the Mull of Galloway a
very considerable cargo of tea, spirits, etc. This is her second trip
since the engagement. The other landed at the Clone on the opposite
side of Glenluce-bay. She was chiefly laden with tea, is
copper-bottomed, and said to be an extreme swift sailer. These vessels
came in company, intending to support each other in case of being
attacked by any of the Admiralty or Revenue cruizers. Their landings
were effected without the loss of any part of the cargoes.
From Leeds Intelligencer - Tuesday 27 January 1784:
Another very capital cargo of contraband goods was landed on
Wednesday and Thursday se'nnight, at the Clone in Glenluce Bay. It
consisted chiefly of tea, and is valued at not less than £12,000.
The vessel that brought it is a cutter, mounting twenty-two 6 and 9
pounders. This is the rarest harvest the smugglers have had for some
years past. There appears nothing to interrupt their labours, people
begin to wonder what is become of the naval force which was ordered into
the channel to put a stop to their proceedings.
From Kentish Gazette - Tuesday 20 December 1785
On Monday se'nnight the sloop Ann, Captain Robb, Garlieston,
from Liverpool to the Clone, in Galloway, was totally lost within two
leagues of that place, with the whole of the cargo, consisting of sugar
and dying stuffs, and four of the crew perished. The Captain, and a
young boy, son of Mr. Dunsmuir, in Garlieston, the owner of the vessel,
were saved.
Thurot's plan was to leave Dunkirk with a group of 5 French warships and sail clockwise around Britain - destroying shipping. Their departure was delayed by a British blockade until 15 October 1759. One of his fleet, Begon, was damaged in a storm and returned to France. They put in to Gothenburg and then Bergen for repairs. On 24th January they were off Loch Foyle, but storms caused another vessel, L'Amarante, to be separated from the rest. The other commanders begged Thurot to return to France, but he insisted that they must achieve some of their objectives. On 13th February, the remaining 3 vessels entered the sound of Islay - where they purchased provisions. They then sailed for Carrigfergus, where they were able to overwhelm the opposition, with the loss of around 100 men, and land the 600 men remaining from the 1270 who had set out from Dunkirk. This weakened force set sail on 26 February. On paper the three French warships were somewhat better armed than the three British vessels sent to oppose them. But morale was low and they had suffered much storm damage with guns moved below deck or thrown overboard, and they were short of stores.
Three French warships: Maréchal de Belle-Isle, Terpsichore and Blonde, under the overall command of ex-privateer Francois Thurot, with many troops aboard, had invaded Carrickfergus for a few days. They then left and were located in Luce Bay by a force of three Royal Navy vessels: Aeolus, Pallas and Brilliant. Off the west coast of the Isle of Man, named as Bishops Court, on 28th February 1760, the battle took place - with the three French vessels being forced to surrender. French casualties were high - over 300 killed - while British losses were only 5.
Painting by Richard Wright of the aftermath of the battle - Royal Navy
vessels with their captured French vessels, in Ramsey Bay.
[From Manx Museum]
An account given by John Kelly from the 26th of February, when he boarded the Aeolus, off the Bay of Dublin, and undertook the pilotage of her to the Lough of Belfast, in quest of three French ships of war.
27th. - About two o'clock in the morning they tacked and stood for
the Scotch shore, the weather being more moderate; about four that
morning, John Kelly, the pilot, and others, perceived the enemy standing
S.E., intending for the Isle of Man: but when they made the English man
of war distinctly, they changed their course by hauling close on the
wind to the Scotch shore, being then somewhat less than a league to
windward. The English men of war hauled their wind, and crowded sail
after them; and about sunrise came up with the Belleisle, and after
Captain Elliot gave her a broadside, she returned it, and then put him
aweather, in order to board the Aeolus, but her bow-sprit coming between
the main and fore shrouds it was carried away, then her stern scraped
the Aeolus and fell astern of her. It was during this time that great
execution was done among the French by the constant firing of the great
and small shot; she then dropping astern, the Aeolus bore down on her,
and gave her a starboard broadside; the Aeolus falling then astern, the
other two English frigates came up and gave the Belleisle a broadside
each, one of which carried away her main yard, and passed ahead of her
to make room for the Aeolus, who was coming up again, an event so close
before he fired, that his bowsprit went in between his main and mizen
shrouds; and in that situation continued firing at each other till the
Belleisle struck; a little while before which the Aeolus carried away
the Belleisle's mizen mast with her bowsprit.
The other two French frigates made but a poor fight, one of them
struck to the commodore, with the Belleisle.
The Terpsichore endeavoured to escape, but was pursued by the Pallas,
who soon came up with and took her
Naval Biography of Illustrious British Heroes, London, 1806, 9th, pp. 293-294.
John Elliott: On the 28th of February they descried the enemy and gave chase, in sight of the Isle of Man; and about six in the morning, Capt. Elliott in his own ship engaged the Belle-isle. In a few minutes his consorts were also engaged with the other two ships of the enemy. After a warm action, maintained with great spirit on all sides for an hour and a half, Captain Elliott's lieutenant (Forbes) boarded the Belleisle, and striking her colours with his own hands, the commander submitted. His example was immediately followed by the other French captains. Though the Belleisle was very leaky, and had lost her bowsprit, mizen mast, and main yard, the victory would have remained longer in suspense, if the gallant Thurot had not fallen during the action. The victor had not even the consolation to perform the last offices to his brave enemy, for his body was thrown into the sea by his own people in the hurry of the engagement. The enemy had about 300 men killed and wounded. The service performed on this occasion was deemed so essential to the peace and commerce of Ireland, that the thanks of the House of Commons in that kingdom were voted to the conquerors of Thurot, and the freedom of the city of Cork was presented in silver boxes to the Captains Elliott, Clements, and Logie. Having re-fitted the prizes, Capt. Elliott got into Kinsale with them, and in his squadron, and from thence proceeded to Spithead, where he arrived on the 26th March soon after which he was introduced to his Majesty and most graciously received.