Lady of Mann was the final vessel in a quartet with Manx Maid of 1962, Ben-my-Chree of 1966 and Mona's Queen of 1972.
She was the second vessel in the line's history to be so named, the first being the company's "centenary steamer", RMS Lady of Mann which entered service in 1930.
The fourth car ferry was ordered from Ailsa Shipbuilding in Troon, Scotland as demand for car space continued.
Lady of Mann arrived in service in 1976.
Known as the "Lady", she was the flagship of the fleet until 1984.

Based on the earlier Mona's Queen, she was 2 inches (51 mm) smaller and had 12-cylinder diesel engines, compared to her elder sister's 10.

Her maiden voyage was the morning sailing to Liverpool on 30 June 1976.
Already several weeks late, she had missed the peak TT traffic, something which caused much stress for the Steam Packet Company.

Lady of Mann remained the fleet's flagship until 1984, when she was replaced by Mona's Isle.
Her owners were in financial difficulties, forcing a merger with Manx Line.

In 1989, Lady of Mann was withdrawn from service for a £2.6 million refit at Wright and Beyer.
She received a complete modernisation of the interior layout, increased vehicle capacity, passenger capacity for 1000, and a new livery; she returned to service on 26 May 1989.
This made her sister Mona's Queen redundant, and she was withdrawn from service in 1990.

Disaster struck on 2 June 1993.
Instead of going astern onto the Victoria Pier in Douglas, she surged straight ahead and crashed into the Battery Pier, crumpling her bow.
She was temporarily repaired, and issued with a lower passenger certificate to operate during TT, after which she was withdrawn for permanent repairs.
The first fastcraft to operate from the island was a result of this, with SeaCat Scotland making a return sailing from Stranraer.

1994 saw the arrival of the first SeaCat to operate for the Steam Packet Company, and HSC SeaCat Isle of Man operated for the company in place of Lady of Mann.
A period of calm weather allowed successful operation for the wave-restricted SeaCat.
Problems at the end of August led to Lady of Mann returning to service, and a drop in passenger numbers, who had been tempted by the SeaCat's high speed.
1995 saw Lady of Mann operate for Porto Santo Line in Madeira.

In 1996, the Steam Packet Company was bought by Sea Containers and all vessels in the fleet were painted in the new owner's blue livery.

After the 1996 TT, Lady of Mann was employed on the new Liverpool–Dublin service, taking around 6 hours to complete a passage.
She was replaced on this service in 1997 by SuperSeaCat Two, and often came to the rescue of the craft due to recurrent technical problems and weather cancellations.
She was joined in 1997 by the new flagship, Ben-my-Chree, the largest vessel the company has ever operated.

Following the 1999 TT period, she was not sent to her usual Madeira charter, but instead retained as a back-up vessel for Ben-my-Chree.
The winter of 1999 led to a long programme of sailings for Lady of Mann, with the fastcraft and Ben-my-Chree unable to operate.
The following year after TT, she was sent to the Azores for a three-month charter.
During the winter of 2000–01, Lady of Mann maintained the company's Douglas–Liverpool services, before entering Cammell Laird yard for a refit to comply with the latest SOLAS regulations, which included a new fast response craft on her starboard boat deck.

Due to the foot and mouth outbreak, Lady of Mann's 25th anniversary cruise to her birthplace in Troon was cancelled, to prevent the disease reaching the island.
This also led to cancellation of the annual TT races.
The following year's TT saw "the highest recorded traffic for about 20 years".
Lady of Mann covered for Ben-my-Chree on 28/29 May 2002 when the latter had to be withdrawn for emergency repairs.

Sea Containers put the Steam Packet up for sale and it was bought by Montagu Private Equity.

During Ben-my-Chree's major refit in 2004, sailings were covered by Lady of Mann and the chartered freight ship Hoburgen.
The island had a record TT season in 2004 af
Lady of Mann was the final vessel in a quartet with Manx Maid of 1962, Ben-my-Chree of 1966 and Mona's Queen of 1972. She was the second vessel in the line's history to be so named, the first being the company's "centenary steamer", RMS Lady of Mann which entered service in 1930. The fourth car ferry was ordered from Ailsa Shipbuilding in Troon, Scotland as demand for car space continued. Lady of Mann arrived in service in 1976. Known as the "Lady", she was the flagship of the fleet until 1984.
Based on the earlier Mona's Queen, she was 2 inches (51 mm) smaller and had 12-cylinder diesel engines, compared to her elder sister's 10.
Her maiden voyage was the morning sailing to Liverpool on 30 June 1976. Already several weeks late, she had missed the peak TT traffic, something which caused much stress for the Steam Packet Company.
Lady of Mann remained the fleet's flagship until 1984, when she was replaced by Mona's Isle. Her owners were in financial difficulties, forcing a merger with Manx Line.
In 1989, Lady of Mann was withdrawn from service for a £2.6 million refit at Wright and Beyer. She received a complete modernisation of the interior layout, increased vehicle capacity, passenger capacity for 1000, and a new livery; she returned to service on 26 May 1989. This made her sister Mona's Queen redundant, and she was withdrawn from service in 1990. 
Disaster struck on 2 June 1993. Instead of going astern onto the Victoria Pier in Douglas, she surged straight ahead and crashed into the Battery Pier, crumpling her bow. She was temporarily repaired, and issued with a lower passenger certificate to operate during TT, after which she was withdrawn for permanent repairs. The first fastcraft to operate from the island was a result of this, with SeaCat Scotland making a return sailing from Stranraer.
1994 saw the arrival of the first SeaCat to operate for the Steam Packet Company, and HSC SeaCat Isle of Man operated for the company in place of Lady of Mann. A period of calm weather allowed successful operation for the wave-restricted SeaCat. Problems at the end of August led to Lady of Mann returning to service, and a drop in passenger numbers, who had been tempted by the SeaCat's high speed. 1995 saw Lady of Mann operate for Porto Santo Line in Madeira.
In 1996, the Steam Packet Company was bought by Sea Containers and all vessels in the fleet were painted in the new owner's blue livery.
After the 1996 TT, Lady of Mann was employed on the new Liverpool–Dublin service, taking around 6 hours to complete a passage. She was replaced on this service in 1997 by SuperSeaCat Two, and often came to the rescue of the craft due to recurrent technical problems and weather cancellations. She was joined in 1997 by the new flagship, Ben-my-Chree, the largest vessel the company has ever operated.
Following the 1999 TT period, she was not sent to her usual Madeira charter, but instead retained as a back-up vessel for Ben-my-Chree. The winter of 1999 led to a long programme of sailings for Lady of Mann, with the fastcraft and Ben-my-Chree unable to operate. The following year after TT, she was sent to the Azores for a three-month charter. During the winter of 2000–01, Lady of Mann maintained the company's Douglas–Liverpool services, before entering Cammell Laird yard for a refit to comply with the latest SOLAS regulations, which included a new fast response craft on her starboard boat deck.
Due to the foot and mouth outbreak, Lady of Mann's 25th anniversary cruise to her birthplace in Troon was cancelled, to prevent the disease reaching the island. This also led to cancellation of the annual TT races. The following year's TT saw "the highest recorded traffic for about 20 years". Lady of Mann covered for Ben-my-Chree on 28/29 May 2002 when the latter had to be withdrawn for emergency repairs.
Sea Containers put the Steam Packet up for sale and it was bought by Montagu Private Equity.
During Ben-my-Chree's major refit in 2004, sailings were covered by Lady of Mann and the chartered freight ship Hoburgen. The island had a record TT season in 2004 af
MS Lady of Mann