Domains with a .ws extension (such as www.ROAT.ws) cannot be transferred to a new registrar. Most domain extensions can be transferred to other registrars but not the .ws. This is a rule set by the .WS Central Registry and not something being limited by the registrar.
So, be careful where you purchase your .ws domains... there are registrars that will sell the first year for very cheap and then the renewals will go up very high and since you cannot transfer the domain to another registrar you will be stuck.
About the only option (and one I wouldn't recommend) would be to let the domain expire and try to re-capture it with an expired domain auction site... but this could cost you if the domain name is desirable and the auction price goes high. The best action is to purchase your .ws domains from a reputable registrar and plan to keep it there forever.
Keep looking for that perfect domain name!
Ron