To answer Alan's question about municipal regulations. For the most part the regulations will be posted or you will be told when you sign into a marina. There are a few designated "NO Discharge" zones. These are well documented on the internet, and often signs are posted. Many places allow MSD type I Llectra-san or Pura-san devices) when on the ICW or some inland waters. Many lakes are total no discharge areas, and may even require that thru hull fittings be disconnected.