Ok, Saw this in a big boat race the other day and am curious if my interpretation of the rules is correct. The Red boat is on Port tack, on the layline to a mark. Their course is also parallel to a shoal. The blue boat is on Starboard, heading towards the red boat and the layline. As the Blue boat approaches, Red, she Hails starboard. Red hails back that she needs water and cannot tack. Blue tacks under Red to avoid a collision and hails protest.

Is the protest valid?? Basically this is a another obstruction situation but i'm not sure how it works if Red could still give way by ducking Blue. My initial reaction is tough poop for Red, they should have ducked. What do you experts say?

T