Does this qualify? Fly UK to Singapore, cruise from Singapore to Shanghai and fly home same day - UK

Cruise details - Hi there - I have 2 UK passport holder doing the following cruise - UK passport holders
They fly home on the 5th January from Shanghai (Pudong) via Dubai to Glasgow - 2300/0515 0720/1130.

Can you confirm please - they do not need a visa and are exempt as per 144-HOUR TWOV EXEMPTION rules?


Gillian

They fly in to Singapore from Glasgow on the 18/12

Sapphire Princess - 21/12 -

Singapore 21DEC18 FRI DEPART 4:00PM CHECK IN STARTS AT 1230P At Sea

22DEC18 SAT Ko Samui, Thailand

23DEC18 SUN ARRIVE 8:00AM DEPART 5:00PM Tender Required WHEELCHAIR ACCESS LIMITED Bangkok (Laem Chabang), Thailand

24DEC18 MON ARRIVE 7:00AM DEPART 7:00PM At Sea

25DEC18 TUE Ho Chi Minh City (Phu My), Vietnam

26DEC18 WED ARRIVE 7:00AM DEPART 6:00PM At Sea

27DEC18 THU At Sea

28DEC18 FRI Hong Kong, China

29DEC18 SAT ARRIVE 7:00AM DEPART 11:00PM At Sea

30DEC18 SUN Taipei (Keelung), Taiwan

31DEC18 MON ARRIVE 7:00AM DEPART 6:00PM At Sea

01JAN19 TUE Busan, South Korea

02JAN19 WED ARRIVE 9:00AM DEPART 6:00PM Nagasaki, Japan

03JAN19 THU ARRIVE 9:00AM DEPART 7:00PM At Sea

04JAN19 FRI At SEA

05JAN19 SAT ARRIVE SHANGHAI 7:00AM