The Uganda Sails Wednesday by Stuart Condie

It's 1960, and pregnant with her lover's child, Heather Fontwell makes a plan to visit her husband William at the tea plantation he manages in Kenya. If she gets there in time she hopes she can convince him that the baby is his so she books passage on the SS Uganda for her and their son Johnny, sending notice to William that she is on her way. In Kenya, William is distracted by secretary Dorothea's news of financial misconduct at the plantation, something that William suspects may be down to Mombasa harbormaster Carruthers - currently on the SS Uganda making his way back to Kenya... During her journey, Heather meets resistance, traveling as a single woman, particularly from the unpleasant Carruthers and bullying turns to danger as her cabin catches fire. She and Johnny are moved to first class, further angering Carruthers and the morning sickness she is hiding as travel sickness is showing no signs of abating. The ship matron is handing out a new anti-nausea medication like sweets and Heather relies more and more on these thalidomide tablets to keep the sickness at bay. Events take a tragic turn before they dock at Mombasa and William arrives at the port to find no wife and a captain and crew who seem to be hiding the truth...