Tuesday, February 26, 2019

Turning Rules for Sailing

I just finished this, so there's no reason not to share.  I will post it on the wiki this evening from my notes, making changes if anyone wants to deliberate on the content below.  The link to turning and to ship hexes are blank pages right now, but will be active tonight.  Other links should work; please let me know if they don't.  This was a crazy difficult set of rules to write.

Figure 1 - Before Making a Left Turn
TURNING (sailing ships)
For sail ships, turning describes three possible manoeuvres. A moving ship going forward may turn left or right; a ship may swing its bow away from the wind; and a ship may swing its stern into the wind, which is to say moving the stern so that the ship’s bow points more directly into the wind.

Moving Forward

Figure 2 - Completing the Left Turn
When logging movement, shipmasters give orders to change course in 60-degree increments, in keeping with the hexed battle map. These turns are governed by ship hexes, so that as the ship turns, the bow traces a line across the adjoining hex, pointing at the hex side that fits with its new orientation. This movement is resolved during the movement execution phase of the sequence of play.

In the example shown of a right hand turn, Figure 1 shows the ship before the turn occurs. The front green arrow indicates the swing of the bow in the new direction. The black dotted line indicates the outer compass of the stern as it swings around to follow the bow.

Figure 3 - Turning Left after Right
Figure 2 then shows the ship in its new orientation, the turn having been completed. It’s former position is shown in white. Note that although the ship has made the turn, it has not perfectly lined up with the ship hexes ~ instead, it now occupies part of five adjoining ship hexes instead of three (ignoring the sails). The adjusted orientation of the ship is 45-degrees from its original heading, which would become 60-degrees if it moved forward one more hex.

Contrariwise, if the ship were to make an immediate left hand turn with its next movement factor, the ship would straighten out again to its original heading (see Figure 3), swinging back 45-degrees, moving so that it was displaced one line of hexes from its original path.

Ships turning in this fashion ALWAYS move by the bow. Each individual turn costs one movement factor of a ship’s total movement allowance. A ship may never make more than one turn per ship hex.

Smaller, nimbler ships are able to make more turns per sequence of play than larger, cumbersome ships. This manoeuvrability is part of a ship’s “yare.” See ship types for more information.

As ships turn, they adjust their attitude to the wind, which in turn can limit their total movement (whether or not accounted for in the movement log). As detailed in the wind effects table, adjusting from one attitude to another can sharply reduce the ship’s forward momentum.

For example, a B-type ship that’s reaching to a gentle breeze is moving a factor of 5 hexes. As it moves, it turns to an attitude where it is now close-hauling, which is a factor of 2 hexes. Whatever its movement before the turn, it may now move a maximum of 2 hexes in that direction. If it has a movement factor left after movement, it can then swing back, reaching to the wind, and spend the rest of its factors. It cannot again turn into a close-hauling attitude. It could run against the wind. Take note that after close-hauling for 1 or 2 factors, if it turned its head to the wind, it would stop in place, and its remaining factors would be discarded until the next movement notation phase.

A ship may never make a turn if the attitude would cause the ship to exceed its movement allowance at the time of the logging movement phase. Thus, if the ship above started close-hauling to the wind, so that it began the sequence of play with 2 factors, it could not move further than 2 factors even if it turned to begin reaching. This wind limit rule can restrict movement, but it cannot add movement!

Note also that the wind limit rule does not limit the number of turns the ship may take (that is limited by ship type), only the number of hexes that a ship may move.

Any ship that turns to head into the wind must immediately stop and cease movement until the next movement notation phase.

Swinging the Bow or Stern

Figure 4 - Swinging by the Bow
When a ship’s movement is zero, it is permitted to swing its bow outwards to the left or right in a manoeuvre that changes the ship’s attitude to where it will close-haul (and move with the next movement notation phase). The manoeuvre is simple, as shown in Figure 4. As the bow swings over, the stern does as well.

Figure 5 - Swinging the Stern
When making this manoeuver, the bow swings while the ship turns on its stern, dropping back slightly as it does so.  Following the maneuver, which puts the ship into a close-hauling attitude, the ship must turn either left or right with its next movement factor.  Thereafter, with each forward move, the ship should come in line with the ship hexes.

Likewise, a motionless ship is permitted to swing its stern (Figure 5). The stern may be adjusted each so that it swings away from the wind, moving the bow towards the wind. In the example shown, the ship’s attitude to the wind is unchanged (close-hauling). Following the move, the ship may either turn in the direction of the manoeuvre (which means it could turn left here) or move straight ahead at least one turn. A right turn from this position would be more than 60-degrees and therefore cannot be accomplished without first moving forward.

The manoeuvre is rarely used, but can be helpful after unfouling or ungrappling from other ships.


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