A Senedd committee has launched an inquiry into the impact of Holyhead Port's closure.
Ferry services to and from Dublin resumed earlier this month, but work is continuing to repair damage in the wake of Storm Darragh last December.
The Economy and Trade Committee says it will call in organisations such as Stena Line - which operates the port - to understand what happened and consider if a similar event can be prevented.
Committee chairman Andrew RT Davies, who resigned as Welsh Conservative leader last month, said: "The impact of the Holyhead Port closure should not be underestimated as it is the UK's second largest passenger port and the consequences of its closure have greatly impacted the local economy, as well as the national economy."
"Our inquiry is asking for answers from those responsible for our critical infrastructure. Passengers, businesses and local communities have all been severely impacted during a very busy period and it's important for us to make sure that we learn lessons for the future."
"When incidents like this happen it's essential that communication with the public and businesses is clear, honest and timely. Storms such as Darragh are hitting the UK more and more often and so it's important for us to be prepared and resilient and do all we can to reduce significant disruption."
The inquiry will focus on what caused the storm damage and its impact, along with communication during and after the storm with port users, communities and businesses as well as between governments.
It will also look at the speed of response in assessing and repairing the damage, including government support.