I've been rereading my 1e books for a campaign that would be set on a series of Caribbean-type islands with the potential for plentiful naval combat. Since I'm not too concerned about realism, the "Waterbourne Adventures" rules from the DMG (pp. 53-55) will be sufficient. However, I am having trouble determining how quickly a ship in motion (particularly a sailing vessel) can turn during combat.
Here's what the rules say about turning (that I can find):
"Any oared ship can move forward from a complete standstill in one round.
Galleys are able to do a pivot only if they are dead still in the water. This
action requires a certain amount of skill or else the oars may be damaged.
Any ship wanting to turn must let her momentum carry her twice her
length before such a procedure may begin."
What this tells me is that all moving ships must proceed twice their length before beginning to turn after being at a dead stop. There is nothing that I can find about how long a turn would take to complete (whether 60, 90, or 180 degrees), though, once a sufficient turning speed is reached – as opposed to the "Aerial Adventures" rules that build on the class ratings to give a sense of how far different creatures can turn per round (my preference would be to find something like that for ships).
Is this something I just need to make up rules to cover? Please note, I've already checked Margaret Foy's article in Dragon #116; it had illustrations of different types of turns, but no timing rules. Even something as simple as "a standard ship traveling at 1/2 speed can turn 60 degrees per __" would be sufficient for my purposes
Best Answer
I checked the DMG, DSG and WSG. All have some rules for ship movement but none of them covers how fast ships turn. DSG and WSG cover smaller craft, the type that a party may take and crew themselves.
Please have another look at that Dragon article. Margaret Foy's article in Dragon #116 does cover turning speed, just not in the way you may hope for.
Ships Under Sail
It goes on to say:
This would indicate that turning a ship is not a simple matter as a x degree turn can take multiple rounds. For example, using the noted table Ia shows that a Longship (base maneuverability rating of 8) of "acceptable" make with an "acceptable" crew will take 1d8 rounds to change the "Point of Sail" from one position to another, say from Port Running Free to Port Board Reaching. That's a simple 30 degree turn. It's not like in the movies where some dude spins a wheel and it's done. There is so much more to do. Sails are trimmed or let out. Yard arms are moved. Rigging has to be climbed so sailors can get in position to make the changes. Yes, the rudder has to be adjusted. So with the bigger vessels this can take several minutes.
As worded, I think one could take the changing the Point of Sail to an extreme and say the same amount of time would be required to make any turn. So the same Longship could go from the Port Running Free position to the Starboard Reaching position, a full 120 degrees, in the same 1d8 rounds. After all your crew is just repositioning sail and rigging so there is nothing that says they have to stop at each intermediate Point of Sail position.
Ships Rowing
Galleys have sails as well as oars. When they are not under sail power they have different rules for movement.
It goes on to say:
The wording is a bit puzzling here but I would suggest that what is trying to be said is that when making a galley (operating under oar power) turn one would use both the rudder and the oars. Turn the rudder and have the oars on one side slack off and/or the opposite side speed up. So, again, the course correction is not an immediate thing. Making the large vessel turn takes minutes and goes beyond the movie wheel spinning.