These are the rules from the 2016 race.

2017 Rules will be released soon.

ORGANISING CLUB Isle of Bute Sailing Club (IBSC), West Bay, Rothesay
CLUBHOUSE PREMISES The IBSC clubhouse will be open - for skippers, crews, supporters, members and sponsors - on the Friday evening before race day, for most of the race day itself, and for the ‘Awards Ceremony’ at approx 8:00 pm on race day.
SAILING RULES The race will be governed by the ISAF Rules 2013–2016.
START & FINISH LINE The line will be from west to east (approximately) in Rothesay Bay, near the IBSC clubhouse. A flagged buoy will act as the inner mark, and an inflatable yellow buoy as the outer mark.
SHORTENED COURSE If conditions are such that the boat leading the fleet cannot cross the Rothesay Bay finish line (as described above) by 16.00hrs then the race may be shortened. To facilitate shortening the course three ‘timing lines’ (as described below) have been identified. Depending on the weather conditions one of these may become the ‘finish line’ on the day. The ‘finish line’ will be the one where the leading boat has crossed before 16.00hrs. All boats following will then have until 19.00hrs to finish. As VHF reception is poor on the west of Bute, notification of a shortened course will be communicated via a text message. In poor reception areas the text will be automatically relayed when mobile reception is possible All racing will cease at 19.00hrs.
TIME RECORDING All participants are required to record the current time (BST) as they cross three timing lines. Written records must be kept. Timing LINE A Line that runs from Colintraive Church (55 * 54.859N 5 * 7.883W) due West as shown below

Timing LINE B Line that runs from the north extremity of Inchmarnock Island(55* 48.316N 5* 9.638W ) due East as shown below

Timing LINE C Line that runs from Rubh’ An Euan Light(56 * 43.798N 5 * 0.222W) due east as shown below.

These timings should be communicated by text on 0754 652 7077. In poor mobile reception areas the text is automatically relayed when mobile reception is possible. When you have GPS on board, or on a mobile phone, the timings can be taken when the GPS reading is greater, or lesser (depending on direction of travel) than the timing line coordinates given above.
HANDICAP The CYCA handicap system will apply. If a boat has not submitted a CYCA handicap with its entry then the Race Committee will allocate a temporary number.
CLASSES Class 1: CYCA 15 minutes/hour, and under Class 2: CYCA 15.25 to 18.50 minutes/hour Class 3: CYCA 18.75 minutes/hour and over Class 4: Restricted ‘White Sails’ only (no spinnaker, gennaker, ghoster etc.,) Participating boats are asked to display a class flag.
COURSE The course, either ‘north-about’ or ‘south-about’ the island, will be indicated by a board displayed at the clubhouse. The decision on which course to set will be taken about one hour before the start. A Red Disc will indicate a ‘north-about’ course. A Green Disc will indicate a ‘south-about’ course. North-About Course (Red) Start - cross the line from south to north. Leave the Isle of Bute to port and observe all navigation marks. Use either channel around the Burnt Islands. Pass inside of Inchmarnock Island. Return to Rothesay Bay leaving the Admiralty Mooring Buoy ( 55*51.4 N 5*02.9 W ) to port. Finish – cross the line from north to south. South-About Course (Green) Start – cross the line from south to north. Leave the Admiralty Mooring Buoy (55*51.4N 05*02.9 W) to starboard. Leave the Isle of Bute to starboard and observe all navigation marks. Pass inside of Inchmarnock Island Use either channel around the Burnt Islands Return to Rothesay Bay (leaving the Admiralty Mooring Buoy to port). Finish – cross the line from north to south.
START PROCEDURE 09.20hrs Time Signal (no flag, sound only) 09.25hrs Warning Signal (Flag ‘1’ raised, and sound) 09.26hrs Preparatory Signal (Flag ‘P’ raised, and sound) 09.29hrs One Minute Signal (Flag ‘P’ lowered, and sound) 09.30hrs Start Signal (Flag ‘1’ lowered, and sound)
CANCELLATION If unforeseen and insurmountable problems arise, the race may be postponed until the following day (at 09.30 hrs) or cancelled. If the race is cancelled, for any reason, it is not possible to refund the entry fee.
PROTESTS Any protests must be lodged with the Race Committee within 30 minutes of the protesting boat finishing. Any decision of the Round Bute Race Committee will be final.
BUTE BOATS Any boats having spent the majority of the 2015 season, and the 2016 season so far, berthed or moored at the Isle of Bute will be eligible for the ‘Best Bute Boat’ trophy.
ENTRY FEE The entry fee of £25 should be paid to the Race Officer before the race.
TROPHIES & PRIZES There will be trophies for the first in each class and prizes for the second in each class. The boat with the fastest overall corrected time will be presented with the Marquis of Bute Trophy. The highest placed ‘Bute Boat’ will be awarded a trophy.
CONDITIONS OF ENTRY The organising club and their representatives disclaim any and every responsibility for loss, injury or inconvenience to persons, boats or associated objects howsoever arising, directly or indirectly, ashore or afloat, from their policy, rules or ruling during racing and related activities.
INSURANCE Every boat must have adequate Third Party and Passenger insurance. The current recommendation is that this should cover claims up to £3.0 million as a minimum.
LATEST INFORMATION To confirm any of the above, and to keep up to date with any last minute changes, contact Bute Race Control on VHF channel 37 or mobile phone 0754 652 7077