What the [expletive of your choice] does this mean?
The fees would apply to boats that arenít registered in Maryland, but are state-documented vessels because they are primarily used here.
In the vernacular lawyerly weasel-speak, it means that many of the federally documented boats with out of state hailing ports that are kept (principally) in Maryland and that also already pay the biannual MD excise/'use' fees (MD 'sticker') are going to be especially targeted for a 1000% tax increase, this would also include the foreign flagged boats.
Its just yet one more forceable extraction of money from the usual but rapidly diminishing prey species to operate an ever increasingly inefficient/bloated government agency .... and with ever decreasing return to those who are forced to pay such 'use'/excise tax. The obvious endpoint is the curtailment and elimination of common prosperity in order to support a quite increasingly affluent bureaucracy/oligarchy.
George III & Co. was less than 1/10000th as 'needy'.