Seafarer union Nautilus International is urging caution as the IMO meets to discuss autonomous shipping.
It warned that neglecting "human factors" could pose big threats to safety and the environment.
The IMO is meeting on Wednesday to kickstart its two-year review of the regulatory framework governing the operation of autonomous ships.
Nautilus has carried out a survey of nearly 1,000 maritime professionals and will present the findings to the IMO on Wednesday.
It shows 84% consider automation to be a threat to seafaring jobs and 85% believe unmanned remotely controlled ships pose a threat to safety at sea.
But more than 60% said they felt automation has the potential to make the shipping industry safer, provided it is introduced in a "hybrid" way.
Helping the humans
This would mean enhancing onboard operations, helping to cut fatigue and excessive workloads, minimising paperwork and bureaucracy, assisting with predictive and preventive maintenance, providing additional support for decision-making, and reducing or even eliminating some dangerous or repetitive tasks.
Nautilus is backing two papers submitted to the meeting by the International Transport Workers’ Federation and the International Federation of Shipmasters’ Associations.
These call for "a degree of caution to ensure that an inappropriate regulatory framework is not hastily put in place in a leap of faith by the IMO on the assurances of technology suppliers."
Nautilus general secretary Mark Dickinson said: "It is absolutely vital that people are not forgotten in the scramble to bring smart ships onto the seas.
"The debate so far has concentrated too much on technological and economic factors.
"Properly introduced, automation and digital technologies could transform shipping in a positive way – making it safer and more efficient – but managed poorly, they could undermine safety and erode the essential base of maritime skills, knowledge and expertise."
"We hope delegates at the IMO’s maritime safety committee will carefully consider the feedback gathered in the Nautilus Federation survey,’ he added.
"There is no kneejerk opposition to technology, but rather a genuine desire to see it used in a way that improves the safety and efficiency of the shipping industry and the working lives of all within it."
