Some reports have suggested that using swimming pools can increase the spread of molluscum contagiosum. This has never been proven, however. It is far more likely that the spread of molluscum is caused by the activities related to swimming. Sharing towels or toys is much more likely to spread molluscum than swimming.
More research is needed to determine how long the virus can last in a pool.
If you have open sores or breaks in molluscum nodules you should avoid swimming to avoid further infection. You should also cover any molluscum outbreak with water tight bandages while swimming just to be on the safe side. You should also dispose of all bandages at how to avoid the spread of infection. Also do not share towels, kickboards or any other pool toys with an infected person