Both tarred marline (tarred hemp) and natural hemp cordage and rope are available in the US (and most likely in the Maritime Providences of Canada), most of which is imported from Hungry. For tarred marline, visit a marine supplier in an area where sailing is popular, many will stock various thickness rolls of tarred marline cordage mostly around 2-5mm in diameter. For natural hemp cordage and rope, most craft stores will have hemp cordage for macramé bracelet and choker jewelry making. Thicker hemp cordage, rope and even hemp fabric can be obtained from sutlers (retailer sellers) of 18th and early 19th century items for historical reenacting/living history. They are around, although it can be a little challenging to find them.

Pete