Distances between the club race marks are provided in the following table.  The overall distance for a race can be approximated by adding the leg distances.

HdGYC CLUB MARKS (distances in nautical miles)
	A	B	C	D	E	F	G	H	Z
A	–	0.14	0.14	0.50	0.87	1.17	0.75	0.53	0.28
B	0.14	–	0.09	0.43	0.84	1.03	0.66	0.39	0.23
C	0.14	0.09	–	0.36	0.76	1.04	0.61	0.42	0.15
D	0.50	0.43	0.36	–	0.43	0.85	0.27	0.42	0.22
E	0.87	0.84	0.76	0.43	–	1.04	0.41	0.83	0.61
F	1.17	1.03	1.04	0.85	1.04	–	0.65	0.64	0.99
G	0.75	0.66	0.61	0.27	0.41	0.65	–	0.48	0.48
H	0.53	0.39	0.42	0.42	0.83	0.64	0.48	–	0.42
Z	0.28	0.23	0.15	0.22	0.61	0.99	0.48	0.42	–

As an example of how to use the table, consider Race 4 of the 2016 Summer Series, which had a Spin course posted of BEZ2, and was started from the dock, at Z.  So the individual six course legs are Z to B, B to E, E to Z, Z to B, B to E, and E to Z.  From the table, the six leg distances are: 0.23, 0.84, 0.61, 0.23, 0.84, and 0.61 for a total distance of 3.36 nm.

You can also use our Google Sheet based distance calculator at https://hdgyc.org/racing/race-committee-and-course-instructions/course-distance-calculator.

Coordinates for club marks are:

Z:  N 39 degrees 32.771′  W 076 degrees 04.936′

G:  N 39 degrees 32.426′  W 076 degrees 04.495′

H:  N 39 degrees 32.899′  W 076 degrees 04.415′

F:  N 39 degrees 32.596′  W 076 degrees 03.680′