The company was founded in 2001 by well known Vaasa-based businessman Rabbe Grönblom, just months after Silja Line had put their traffic on Kvarken / Merenkurkku to an end because of a decision in the EU to stop taxfree sales on travels between member states.

RG Line bought Silja's M/S Fennia and renamed her to M/S Casino Express, the ship was put in traffic on the route Vaasa–Umeå on 16 May 2001.

On 23 November 2004 RG Line announced that they had bought the ship M/S Kahleberg, which has more capacity for cargo and takes less passengers than Casino Express, which it will replace.

On 24 November, one day after RG Line informed the public about the purchase of their new ship Kahleberg, bad luck struck the company.

On 26 November, RG Line announced that they had chartered M/S Alandia from Eckerö Linjen to temporarily sail for the company while Casino Express was being repaired in Estonia.

Alandia is a well-known ship for people in the Kvarken region, as she had been trafficking for Vasabåtarna for thirteen years as Botnia Express before she was sold to Eckerö Linjen.

Alandia, which at the time of Casino Express' accident was laid up in Eckerö, was sent to a repair shipyard in Stockholm to fix a broken propeller.

For the school's winter holidays, when travelling between Sweden and Finland rises, RG Line had to charter the now repaired Alandia, which have a higher passenger capacity.