Panama tourist Visas are normally 6 months (many other CA countries are 90 days). I've heard you can get one issued in conjunction with your boat's 1 year crusing permit
that is also 1 year in duration, but have never requested such.
If you plan to drive in Panama then your foreign liscence is only valid for 90 days from your date of entry...and the traffic cops do check.
Many expats hop over to CR to reset their Visa...some have been doing this for years, but I've heard grumblings from Panamanian officials about this practice (in the context of soing it long term).
is not far away either.