A week of action to protect the labour rights of seafarers and to highlight rogue employers will begin in Dublin tomorrow.
It is part of an EU-wide initiative organised by the International Transport Federation (ITF), to which Siptu is affiliated.
ITF inspectors, dockers and union volunteers will board and inspect vessels in 16 European countries this week to ensure that workers' conditions are acceptable. Union officials will also recover owed wages and put vessels under ITF agreements to protect vulnerable workers.
Siptu president Jack O'Connor said the week of action was essential because much more needed to be done to provide workplace protection for seafarers. "At present, major shipping companies are able to charter out the crewing of vessels to agencies that employ Third World crews with Third World pay and conditions," Mr O'Connor said.
"As an island economy, where over 90 per cent of goods are transported by sea, this situation is neither morally justified, nor economically sustainable in the long term."
Norrie McVicar, ITF co-ordinator for Britain and Ireland, said the Irish campaign would focus on ferries and roll-on roll-off vessels operating in the Irish Sea.
He expressed his concern about the Irish Ferries' decision to make more than 400 staff redundant and replace them with cheap labour. It subsequently emerged that Irish Ferries had received €4.3 million from the State towards the cost of statutory redundancy payments.
Mr McVicar said "a whole host of companies" were involved in the so-called race to the bottom.
"Some companies are paying as little as £1.90 an hour. That's not much more than €2," he said.
The ITF has more than 100 inspectors who operate under a UN mandate to enforce compliance with international labour standards.
Mr McVicar said ships could be blacklisted if working conditions were found to be unacceptable. He said ships would be investigated to see whether they were flying a national flag or a flag of convenience. Some flags of convenience vessels are ships which are registered by the owners in countries with lax shipping regulations.