Rigging Mechanic

When a ship is underway and not in combat, it moves at its waterborne speed.  While this happens, various crewmembers perform rigging -- moving the ropes and sails about the ship to optimize the use of the windpower.  It seems that this operation should assist the waterborne speed, so I am proposing this mechanic for that.

• Rigging only works on sailing ships.  The amount of sails of a ship is measured in squares in Pathfinder, ranging from 5 or 10 for a small boat to 90 for a large sailing ship.  ( I exclude the 240 squares of the massive Treasure Ship, which is out of sorts for this sort of thing).
• Each ship gets 1 rigger position per 10 square of sails.  Based on that:
• Galley
• 90 Squares
• 9 Riggers
• Junk
• 90 Squares
• 9 Riggers
• Keelboat
• 20 Squares
• 2 Riggers
• Longship
• 30 Squares
• 3 Riggers
• Raft
• 0 Squares
• No riggers
• Sailing Ship
• 90 Squares
• 9 Riggers
• Ship's Boat
• 10 Squares
• 1 Rigger
• Warship
• 40 Squares
• 4 Riggers
• Each rigger helps to make the ship go faster, if he does his job well
• DC 10 Rigging Check (with modifiers for conditions) based on Strength
• For every 5 a rigger misses the Check, it is a -1 to waterborne speed
• For every a rigger succeeds over the DC, it is a +1 t0 waterborne speed
• Rolls are made once per day while underway.

For example, on a warship, the wind speed of the ship is 30.  There are 4 riggers.  Here are some roll combinations:

• Rolls: 12, 15, 3, 9
• 12 -> Neutral, No Plus or Minus
• 15->Positive, +1
• 3->Negative, -1
• 9->Neutral, No plus or minus
• Overall: Speed is unaffected