Bordeaux airport is located in Mérignac (12km from Bordeaux downtown). The airport provides connection to many French and European cities. See details here. Bordeaux is also directly connected to Montreal. (See Air Transat website for available dates.)
A shuttle (Jet’Bus) connects every 45 minutes Bordeaux Airport to Bordeaux train station. (Cost for a one-way journey: 7 EUR. Journey time: 30 to 45 minutes depending on traffic.) A taxi from the airport to Bordeaux train station (and Bordeaux downtown) costs about 50 EUR and takes approximatively 30 minutes. From there, many trains go to Arcachon. Another possibility is to take a taxi at the airport to Pessac train station where most trains from Bordeaux to Arcachon make a stop. (Cost of a taxi: 25-30 EUR. Journey time: around 20 minutes.) [For train information, see next section.]
In some situations, it might be convenient to fly to Paris and then to take a high speed train (TGV) to Bordeaux. It is even possible to take a train from Paris airport (Aeroport CDG 2 TGV) to Bordeaux. Travel duration of such trains is approximately 3 hours (2 hours from Paris downtown). [For train information, see next section.]
Finally, it is possible to take a taxi from Bordeaux airport directly to the conference venue at Arcachon. (It would cost about 100 EUR and would take approximatively one hour.)
The national train operator SNCF offers several trains per day from Paris (Montparnasse train station) to Arcachon and many more to Bordeaux.
Frequent trains connect Bordeaux to Arcachon in approximately 50 minutes. The cost of a train ticket ranges between 7.50 and 9.60 EUR. Note that it may be more convenient to go by Taxi to Pessac train station when coming from Bordeaux airport.
Arcachon can be easily reached from Bordeaux by taking the A63 and then A660 highways.
You can find hotel rooms using this official service of Arcachon city.