I am making up a 'B' rig for my IOM which has bowl type deck. The Gooseneck I have has quite a low adjustable bar which could easily foul the rim of the mast bowl if it is set too low. I see that in Frank Russell's diagrams the distance from the deck to the lower band is 70mm. If I have to exceed this will this be legal I.e. is there any stipulation in the rules about this? Could rule gurus please advise?

Hi, I’m no expert but the class rule below might answer your question.

C.7.4 MAST
(a) DIMENSIONS
minimum maximum
Lower point to deck limit mark
as defined in D.1.5 ....................................... 60 mm ... 100 mm
Within these limits, the variation in height of
lower point for each rig .......................................... ..... ± 5 mm

IOM 2021 Class Rules, section C.7.4 lays it out for you.

Deck limit mark to lower point (mast band) is between 60mm and 100mm (these are absolute limits) but more importantly this distance must be the same on all your rigs  with a 5mm plus/minus tolerance. So if your A rig measurement is 70mm then your B rig must be between 65mm and 75 mm.

Hope this is clear

Many thanks for the info. The consistency across rigs is the killer here. Important to get this right (especially as Phil is our Club Measurer!) I'm going to get one of Peter Wiles bendy kickers which should solve my problem. Every day is a school day!

the bendy kickers work quite well, there is also the option of changing the height of your other rigs bearing in mind the 60 to 100 mm maximums