Correction - The Narrow boat

A problem presents itself: the AD&D 3.5 rules quote the row boat moving at about one and a half miles an hour.  Silly me, I put the smugglers’ beach 10 miles from the coast, and the mansion right on top of that.  10 hours of hard rowing is no way to get rich quick, let alone escape the mansion. I am now reviewing possible motor boats of the period to salvage this bit of fiction.

EDIT: this was a terrible problem to research.  I will spare the many failed avenues and skip to the finish.

The core problem is that I need a boat that will be reliable to carrying quantities of cargo (read tons) through a passageway that narrows to about 15 feet at the closest (anything more would either be noticeable or would open up sink holes in the surface).

Salvation from Wikipedia, assuming that its correct:

“Narrowboat,” Wikipedia, retrieved 20 March 2012, last updated 25 February 2012, available online at http://en.wikipedia.org/wiki/Narrow_boat.

Narrow boats are custom tools created for the navigation of rivers in Great Britain, where the minimum width of the locks or bridges holes can be 7 feet.  They cannot be greater than 7 feet, so make it 6 feet and keep it low to the water level to avoid making it tippy.  It’s length can be up to 70 feet long.  And it has a made to order reason to exist in Britain!  Bonus.

Okay, so there is a possible tactic to use.  One boat, 6 feet wide by (70-2d20=) 50 ft.  It floats in the water, but shallow, maybe up to 5 feet down.  It should be 10 feet up and no more than 20 or it tips.  This is a river craft, so it will be a risk in the North Sea.  You know what, let’s have them meet an existing river close to the coast.  The smugglers arrive by night, drop off cargo and leave it for the boaters.  The boaters arrive and take it before the authorities find it.  If the authorities get involved first, both parties deny all involvement.  This boat should not go into the North sea directly. 

That necessitates a change, but I spent hours on this so screw it.  The underground river runs to a thick wood several yards across, which is adjacent to the coast.  The overseas smugglers drop cargo on the coast.  If they are caught by the Royal Navy, they deny everything they can, if not caught, they drop their cargo under dead of night and go.  Payment reaches them afterwards, secured by the Baron.  Bringing horses and carriages with the Narrow boat to collect the cargo on the beach is proving another challenge, but it can be done with some complex logistics, and it shouldn't be impossible to sell the PCs on that scenario.  The wagons bring the cargo overland through the yards of dense forest to the open air part of the river.  The narrow boat has a swell or lake in the river to turn around, or better yet, just uses a diesel powered tug which can turn around much more easily.

This gives the smugglers, and the PCs, up to 20 tons of cargo, and unpowered it belongs in the 19^th century, and the century before and the century after.  A tug was added in the 20^th century to increase speed, which was a long diesel powered boat maybe 30 ft long and again 6 feet wide.  This should come with long guide ropes which would be removed from the water after the voyage, but found nearby.  The engine was diesel, but had to carry its own engines, its fuel, and the operator/navigator.  Two persons could be accommodated on the lead ship while 20 tons of weight/cargo/ passengers can sit in the back.  The narrow boat includes accommodations for an entire family of “river folk” to live and work off shore.