Chesapeake Bay Swim - Charted
by John Walker
View Looking South (in other words, you swim from right to left and this
is what you see when you look/breathe to your right)
====> Swim Direction ====> Swim Direction ====> Swim Direction ====>
Main East
Channel Channel
S ^ ^ H
a /|\ /|\ ^ ^ e
n / | \ / | \ /|\___/|\ m
d / | \_/ | \ / | | \ i
y____________/___|_______|___\_____. . . __|__|_____|__|____ n Bridge
Deck
| /| | | |\ | | | | | g
P | / | | | | \ | | | | | w
o |/ | | | | \| | | | | a
i XXX XX| | | | | |XX | | | | y
(X=rocks)
n ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ s
Water
t 32# 42# 52# 62# 72# 82# 63# 73# 83# 93# XXX Support#
1.3 1.55 1.85 2.1 3.0 3.3 Distance
mi mi mi mi mi mi
I find it very helpful to have lots of intermediate goals during
the bay swim. First is getting between the bridges. Next is
getting past the curve in the bridges where you can see just about
the entire length of the spans. Following that, I focus on the
beginning and end of the channels and the buoys at each mile (if
I can see them). But the stretch from the end of the east channel
until we exit from underneath the bridges always seems like it
goes on forever. During this stretch, I've always noticed the
numbers painted on the supports of the south/right span and
wondered how I could use this information to help me. The supports
were generally numbered in order but there was one spot where
there was a big jump in the bridge numbers that always confused
me.
While driving over the other span one time last year,
I noted the sequence of numbers on all the bridge supports.
There are basically three sets supports. Within each set, the
numbers increase as you travel east, so you can easily gauge
where you are within the sequence (although the supports are
not all the same distance apart).
Here they are:
Sequence 1: Go from #1 at the west end of the bridge to #29. Since
these supports are so close together and we are generally
closer to the north span at the beginning, I've never noticed
this set during the race.
Sequence 2: Go from #1 to #57. This set of supports includes both
channels. Since I focus on other things until after the
east/second channel, I don't pay much attention to these
numbers until after that channel.
Sequence 3: Go from #30 to #65 (like a continuation of the first set).
If you are not prepared for it, reaching this set of supports
can be disheartening. You are making good progress, the supports
are numbered in the mid-50s, and then suddenly you are back in
the low 30s! You finally exit the bridges around #60 in
this set of supports and do the last 700 yards along the
rocks to the finish.
Measurements of interesting markers:
While driving over the bay bridges a couple times, I noted my car
odometer readings at several intermediate points. From that, I was
able to estimate the distances of various segments of the swim.
A few notes:
1. All odometer readings were based upon landmarks on the South/Old Span.
When I was on the new span, I estimated when I was even with those
points on the old span (using bridge supports on opposite sides of
the old span to guide when I was even with them).
2. Obviously, the odometer readings reflect the distance along the span I
was driving (despite the fact that I used "landmarks" on the old span)
3. I do not take into account any extra distance covered in order to move
sideways from the start to the spans or from the north span to the
south span.
4. My car odometer only goes down to 0.1 miles, so I estimated the
1/100ths.
5. I have no idea how accurate my car odometer is. But it should be at
least consistent enough to give a good idea of relative distances.
Best Guess Eastbound Westbound
Dist. Seg. Odo. Dist. Seg. Odo. Dist. Seg.
from Dist. from Dist. from Dist.
S.Pt. S.Pt. S.Pt.
----- ---- ----- ----- ----- ---- ---- -----
Sandy Pt Beach 0.00 20.24 0.00 11.65 0.00
end of jetty 0.15 0.15 ???? ??? ??? 11.50 0.15 0.15
style change* 0.63 0.48 20.87 0.63 0.63 ???? ??? ???
Main Span
#23 1.32 0.69 21.68 1.44 0.81 10.33 1.32 1.17
(144,132)
#24 1.41 0.09 21.78 1.54 0.10 10.24 1.41 0.09
#25 1.55 0.14 21.92 1.68 0.14 ???? ??? ???
main channel
#26 1.87 0.32 22.25 2.01 0.33 9.78 1.87 0.46
#27 2.02 0.15 22.40 2.16 0.15 9.62 2.03 0.16
#28 2.11 0.09 22.50 2.26 0.10 9.54 2.11 0.08
East Span
#36 2.99 0.88 23.36 3.12 0.76 8.66 2.99 0.88
#37 3.08 0.09 ???? ??? ??? 8.57 3.08 0.09
east channel
#38 3.25 0.17 23.61 3.37 0.25 8.40 3.25 0.17
(25,26=9+17)
#39 3.34 0.09 23.70 3.46 0.09 8.31 3.34 0.09
57/30 # change 3.78 0.44 ??? ??? ??? 7.87 3.78 0.44
Rocks 4.25 0.47 24.64 4.40 0.94 7.40 4.25 0.47
(94,91=44+47)
Finish 4.65 0.40 25.03 4.79 0.39 7.00 4.65 0.40
My best guess as to the minimum distance Bay Swim intermediate points:
total distance segment distance
miles (yds) miles (yds)
Sandy Pt Beach 0.00 0.00
end of jetty 0.15 (264) 0.15 (264)
style change* 0.63 (1109) 0.48 (845)
Main Span
#23 1.32 (2323) 0.69 (1212)
#24 1.41 (2482) 0.09 (158)
#25 1.55 (2728) 0.14 (246)
main channel
#26 1.87 (3291) 0.32 (563)
#27 2.02 (3555) 0.15 (264)
#28 2.11 (3713) 0.09 (158)
East Span
#36 2.99 (5262) 0.88 (1549)
#37 3.08 (5421) 0.09 (158)
east channel
#38 3.25 (5720) 0.17 (299)
#39 3.34 (5878) 0.09 (158)
57/30 # change 3.78 (6653) 0.44 (774)
Rocks 4.25 (7480) 0.47 (827)
Finish 4.65 (8184) 0.40 (704)
* - By "style change," I am referring to the place where the bridge
supports
are of a different style (I don't know enough about bridge building
to specify what type of bridge each section is).
Comments:
I found it interesting that there was a 0.14 mile (246 yd) difference
in the distances measured along the two spans. While the amount seems
intuitively high, the concept seems correct. The old span is the one
that takes a more curved route over the bay. It also swings wider than
the new span almost entirely near the western shore. Once you reach
the main channel, the two bridges are angling back towards each other
slowly enough that they are quite close together again by the time they
reach the eastern shore.
But this distance difference shows that in order to get the best time,
the proper strategy is to stay near the north span at least until you
finish swimming through the bend in the bridges. Of course, if your
goal is simply to finish, you may want to give yourself more clearance.
And if the current is flowing to the north at the beginning and you
simply want to finish, then head towards the south span to give yourself
a little extra margin of safety (and to get away from the large number
of swimmers near the north span).
Swimming strategies:
I outline strategies for two different goals in the two current conditions
in which the race is held.
The first goal is for people who want fast time and have the confidence
that they will not get swept under the bridges by the current.
The second goal is for people who simply want to finish and give themselves
the maximum safety margin from getting pushed under the bridges by the
current.
Flood Tide
- current goes from right to left (south to north) at beginning and
left to right (north to south) later.
Goal : Fast Time
Stay near the north span through the curve.
Continue staying near the north span until the tide shifts.
After tide shifts, let the current carry you to the south span.
Swim fairly close to the rocks to the finish (use them to keep you
swimming straight).
Goal : Finish
Stay in the middle or closer to the south span at the beginning.
Move towards the north span as the flood current lets up.
Stay by the north span until almost to the end.
Let current push you to the south span just before you exit from
between the bridges.
Swim fairly close to the rocks to the finish (use them to keep you
swimming straight).
Ebb Tide
- current goes from left to right (north to south) at beginning and
right to left (south to north) later.
Goal : Fast Time
Stay near the north span through the curve.
Swim straight for the end of the bridges and let the current
push you to the south span.
Continue staying near the south span until you exit the bridges.
Swim fairly close to the rocks to the finish (use them to keep you
swimming straight).
Goal : Finish
Stay near the north span through the curve.
Continue swimming by the north span until the current begins
to let up.
As the current begins to let up, let it push you to the south
span.
Swim by the south span until it is time to exit from between the
bridges.
Swim fairly close to the rocks to the finish (use them to keep you
swimming straight).