There are more definitions but these do not lend themselves easily to illustration. For the complete list and text of Definitions in the RRS, click here.

In essence, the leeward side of the boat is the side on which the mainsail is (or was, if you're head to wind). The other side is - obviously? - the windward side.

Since Heider Funck in W6 is overlapped with W3854 (Uncle Al) and off Al's leeward side, W6 is the leeward boat and Uncle Al is the windward boat - oddly enough.

When you face the bow of the boat, the side to your right is the starboard side, and the left side is the port side. Here the left (port) side of John Weakley's Opti is her windward side, and she is thus on port tack.

W7663 is clear ahead of Laser 61007 and W286 since the latter are behind an imaginary line drawn at a 90º angle to the centreline of W7663 (i.e. abeam) through the aftermost tip of W7663's rudder blade (i.e. the aftermost point of her hull and equipment in normal position). Even if a brightly visible spinnaker sheet, for example, was dragging several metres behind W7663, the other two boats would still not be overlapped with 7663 since that would be equipment not in its normal position.

Y-Flyer 1760 (r) is overlapped with Peter Rahn (black hull) since not all of his hull and equipment are aft of the (imaginary) line drawn abeam from the aftermost point of Peter's hull and equipment (in normal position).

The red vertical line through Hans Gottschling's spinnaker in the above photo illustrates that the bow is not necessarily the forewardmost part of a boat's hull and equipment. For example, on a spinnaker run, a boat whose bow is a few centimetres short of gaining an overlap, may well have that crucial overlap due to her spinnaker.

The sharp turn Uncle Al is initiating on the starting line above, will soon give Doug Netherton (left) a leeward overlap as the red line swings around dramatically with the aft part of Al's boat.

Above, Uncle Al (9355) has an overlap on Søren Jensen (10212) because Sten Madsen (9067) is between them and overlaps both 10212 and 9355. Just in time to get buoy room it was, too!!

Once W9235 and W7700 (above right) reach the zone around the red mark I have "drawn in" (it was down there somewhere - I know! I nearly hit it!!) the term overlap can be applied between them because Rule 18 applies. So, if Roger Shepherd (7700) can just turn on the afterburners, he can get an overlap in time to claim "mark room/water" from Brian Jeffs (9235).

Above, W864 (Nick, blue hull) has just tacked across the finish line and has finished. But he has not yet "cleared the finish line" and is therefore still racing. If Nick had tacked a second or two later, he might have fouled Gale Shoemaker (red hull).  In that case, Nick would have had to do his penalty turns and finish one more time - this one to count!! Likewise, a one-turn penalty followed by a re-finish will be required, if Nick should hit the finish mark - even after getting his “beep”.

Al's note: There is no longer a definition of "tacking" in our "new" Rules. The old Rules more or less defined tacking as the period of time from the moment a boat turns beyond head to wind until she is on a close-hauled course. That definition must now be inferred from Rule 13 as follows:

In the photo above, W825 (Ed Tait) is the leeward boat and has right-of-way. Since CL523 (Colin Junkin) has an inside overlap however, 825 is required by Rule 18 to give 523 mark-room. This means that 523 is expected by the Rules and the above definitions of room and mark-room, to sail to the mark in a seamanlike manner, i.e. keep his boat under reasonable control for the conditions, get his board down in time for the upcoming beat, get his sails in promptly and round as close to the mark as prudence and good seamanship would indicate in the prevailing conditions. In the conditions above, with the mark and the boats bouncing around, 523 is entitled to more room than he would be in 5 knots of breeze, flat water and no current. Once at the mark, the new mark-room definition entitles 523 to sail proper course until he is no longer "at the mark", at which point 523's mark-room protection ends and he must again keep clear of any right-of-way boat(s).

Above, Len Macdougall in Wayfarer 6732 (on port tack) has kept clear of Nick Seraphinoff in W864 who had no need to take avoiding action. W2960, Don Thwing, on the other hand, has reached the danger zone: Within the next second or so, Nick in 864 will have to begin avoiding action or face breaking Rule 14 in a possible collision with 2960. Unless 2960 tacks immediately (or far more riskily, bears away radically now), he will not be keeping clear of the starboard boat, 864, and will have fouled the latter.

In the photo above, Marc Bennett (W6) is keeping clear of Tanya Wharton in the white-hulled Wayfarer to leeward of him, but Tanya has sailed so close to W3854 that Uncle Al can no longer "change course in both directions without immediately making contact with the windward boat". Ergo, Tanya is not keeping clear of 3854 and has fouled Uncle Al under Rule 11.

There is a widespread belief that proper course is the same thing as sailing the rhumbline (i.e. straight towards the next mark) on anything except an upwind leg of the course. This, in fact, is rarely the case. In the photo above for example, Rule 17 requires Colin in CL523 not to sail above his proper course because he became overlapped from clear astern within two lengths of Ed (W825). But that does not necessarily mean Colin must sail straight at the next mark. He is simply required to sail the course that he feels would get him around the course in the fastest possible time "in the absence of the other boats referred to in the Rule using the term", i.e. W825 would be the "other boat" (the windward boat, in this case) referred to in Rule 17.

Here, Colin (CL523) can defend sailing high of the mark if he can convince the Protest Committee that because the spinnaker reach was quite close, he has been sailing high of the mark for some time since he wanted to make sure he would lay it. In other words, he would have sailed above the direct course to the next mark, even if Ed in W825 had not been there.

Before the start, we have no particular place to go, and there is, logically enough, no proper course before the start signal is made. Therefore, Rule 17 which requires sailing no higher than proper course in some circumstances, does not "kick in" until after the start signal has been made.

Upwind, proper course is basically any close-hauled course that a boat may choose to sail. Above, Chris Lansdown in W4678 (the leeward boat) can pinch as high as he likes and Gary McIlroy in CL2679 (windward) will have to keep clear.

Worrying about sailing proper course upwind usually only happens just after the start: Let us assume for example, that these two have just started and that 4678 established a leeward overlap from clear astern while 2679 was "sitting" on the line with her sails luffing and waiting for the "gun". Once the gun went, 4678 became subject to Rule 17 which limits 4678 to sailing no higher than his proper course. Thus, W4678  had to bear away to close-hauled as soon as the start signal was made but is entitled to sail her proper course. If that is higher than 2679 is able to point, tough beans!! (Al's note: this is not the official ISAF terminology)

Apart from the obvious but rarely met obstructions such as piers sticking out in front of us or a ferry coming across, the obstructions that we face most regularly are right-of-way boats of which we must keep clear, boats to whom we must give mark-room, or capsized boats. The photo above illustrates a very common situation: 1305 is on starboard. Since both port boats will very soon have to take avoiding action for 1305, she ranks as an obstruction to both. The leeward port boat (1131) could have called for "room to tack" for the obstruction (see Rule 20) or chosen to pass astern of the obstruction (1305). If 1131 chooses the latter course, she must - under Rule 19 - give room to 171 if the latter also wants to pass astern of 1305. It's very much as if 1305 were a moving mark.

Actually, “fetch” is what the Brits (and others?) say instead of “lay” - as in “Can we lay it yet?” Even being Canadian, I do find “fetch” useful though, when I need to use it as a noun, e.g. “The beat had turned into a fetch.” (= one-tack beat) where the noun “lay” might sound odd to some.

Stephan Nandrup-Bus (W4898) finished just a split second ago when the first part of his spinnaker broke the plane of the finish line. If his spinnaker had been allowed to flap loose to fly further forward, or if his crew - God forbid - had been hanging off the bow with an arm stretched forward, that would not have been gear in normal position and the finish would have been taken at the moment the first part of his boat that was in normal position crossed the line - likely his little mini-bowsprit (spinnaker sheet catcher).