Docks & Pilings
The Coco Plum Experience
Choosing Another Location
Knots and Lines
Cleats, Chocks and Pulpits
Windows & Hatches
Securing the Interior
have been in a "quiet" period, but the current pattern
seems to indicate a very active cycle. That's good reason for boat
owners to give special attention to this year's hurricane season.
(- Posted spring 1996.)
is said that black clouds sometimes have silver linings. If there
is any lining at all, yet alone a silver one, in the last three
hurricanes that have struck Florida, it is that we have learned
that there is much more that boat owners can do to protect their
vessels than was previously believed.
doesn't have to happen to your boat. With narrow slips and
entirely inadequate pilings, the boats in this marina never
had a chance. Numerous cleats and pilings lagged into the
concrete docks came loose.
contrast between the effects of Opal that struck the Panhandle and
Andrew that hit south Dade County is striking. One thing we've learned
from these storms is that the central and southeast coast offers
much greater protection than other areas of the state such as the
west coast and panhandle. Another is that good preparation and choosing
the right location for storm shelter can substantially reduce storm
damage. In addition, fully half of all those boats that were severely
damaged or destroyed were the result of owners who took inadequate,
or no protective measures at all. Those boats that suffered the
least damage were not just lucky; they had owners who were most
knowledgeable about hurricanes and made the best preparations. My
study of the last four storms, especially Andrew, indicates that
overall boat loss and damage could easily be reduced by as much
as 50% if boat owners were better educated about how to protect
their boats. The information in this article is based on a 4 year
study involving nearly a thousand boats. I'll review many of the
things that were learned, plus give some new tips on what you can
do to minimize loss and damage.
normal hurricane approach zone to South Florida extends from
east to south. This is the danger zone for boats. Notice that
the most dangerous winds will tend to be from an easterly
direction regardless of the direction of approach.
Versus Docks My estimate of the survival rate of boats
at anchor in the last four storms is between 5-10%, depending on
location. That really says it all as far as anchoring is concerned.
There are simply too many unknown factors involved for mooring to
be reliable, and there's a long list of reasons why. The use of
anchors for secondary holding, or to keep boats away from docks
is fine, but dependence on anchors almost invariably fails. Certainly
there are exceptions to this, but unless you have a great deal of
certainty about the holding ground and other conditions, anchoring
is a poor option.
recommendation is that anchorage should be avoided whenever possible.
Its better to put a boat up in the mangroves rather than taking
a chance that it will end up against a concrete dock, sea wall or
Ashore Beware that boats ashore do not fare well because
they're up high and offer too much wind resistance. They stand about
a 90% chance of being blown over. Sailboats stand no chance of remaining
Boats By far, the best option for trailer boats is to get
them off the trailer and on the ground with the bow facing east.
Otherwise, the wind will get under the hull and lift it right off,
usually flipping it over. On average, powerful, fast-moving storms
only dump about 5-6" of rain so you can put some water in the
hull to weight it down without worrying too much that it will fill
up. In any case, fresh water damage is better than it being blown
illustration shows the hurricane direction wind zones relative
to the eye. By understanding wind directions relative to storm
direction, knowing where your boat will be relative to the
storm helps determine the direction of hurricane force winds
that it will be subject to, as well as how much storm surge
Direction The geography of southeast Florida provides certain
advantages for boat owners. One is that the most dangerous storms
approach from the east to south quadrant. Storms approaching from
any other direction will not have the same devastating effect because
there will be no storm surge. Another is that the proximiaty of
the Bahama Banks and the narrowness of the Gulf Stream has served
to limit storm surges to considerably lower than what is predicted.
However, this protection factor decreases somewhat in proportion
the the intensity of the storm.
to the eye, there are three major wind zones in a hurricane, north,
center and south. The north zone will experience winds mainly from
the east. In the central zone, the eye, the winds can be from all
directions. In the south, the worst winds will be westerly, causing
a low, rather than high water problem. The north zone of a hurricane
usually has winds of longest duration.
the National Hurricane Center's strike probability estimates to
estimate which side of the storm you're likely to be on. This will
give you a better idea what to expect, and be better able to prepare.
If you're on the south side, you don't have to worry about storm
surge, but the opposite effect, low water. Most boats wrecked on
the south side of the storm resulted from cleats pulling out and
lines parting because there was insufficient slack to allow for
extreme low water. If the storms course is fairly constant, you
can prepare for this. If not, the best you can do is attempt to
choose a happy medium.
that the water level difference from extreme highs and lows can
easily be 20' and you can't prepare for both. If you prepare for
high water and end up on the south side, your best efforts will
be defeated. However, if you live close to your boat, you may get
a 6-8 hour window of opportunity to make adjustments. If your boat
will be on the north side, it will usually become fairly obvious
with adequate time to prepare for extreme high water.
domino effect occurs when one boat on a canal breaks loose
and crashes into others, resulting in a chain reaction that
ends up with boats piled up at the end of the canal.
The majority of boats in south Florida are docked on the hundreds
of miles of man-made canals. In years past, cross-tying was illegal,
but that law has since been repealed and many people now take advantage
your boat fully across a canal has advantages only under certain
circumstances. First, one can't do it too early because you block
access for other boats. People who've tied across canals 36 hours
in advance have been known to have their lines cut by their angry
neighbors. Be considerate: the generally accepted practice is not
to cross-tie more than 12 hours in advance. Be neighborly and consult
with other residents on your canal and make sure that at least a
half-dozen neighbors have your name and phone number so that they
can reach you, especially if you're not a homeowner on that canal.
disadvantage is that tying across certain canals is vulnerable to
what we call the domino effect. In south Florida, it is mainly the
east-west canals that are most vulnerable because that's the usual
direction of wind and storm surge. On the other hand, north-south
canals will be closer to perpendicular to the wind and waves, and
therefore have better much protection, and are much less vulnerable
to the domino effect.
domino effect occurs when boats at the head (windward) of the canal
break loose and are driven downwind, crashing into all the other
boats that are cross-tied. In the aftermath of Andrew, hundreds
upon hundreds of boats on east-west canals were found piled up at
the end of canals, most of which were cross-tied. Those on north-south
canals did not suffer this fate.
when contemplating whether to cross-tie, consider whether the yacht
will be vulnerable to the domino effect. Boats at the west end of
the canal are far more vulnerable than those near the head (east
end) of the canal. If possible, try to check on the mooring of the
boats upwind of you. If someone's done a lousy job, or has tied
to weak or rotten docks, then chances are that his boat is going
to wreck yours. You'll probably stand a better chance if you can
use anchors to stand off from the dock, or find a better location,
rather than being a sitting duck at the end of the canal. If you
can generate a neighborhood team effort, so much the better. Get
all the boat owners involved and insure that all boats are well
secured. The point is, beware of the dangers from upwind.
slip clearance of only two feet, there was no way to protect
this yacht from battering against the pilings.
& Pilings Low dock pilings are one of the biggest destroyers
of boats during a hurricane because of storm surge lifting the boats
above the pilings which then puncture the bottom or hull sides.
If the boat is going to stay at the dock, one of the most important
considerations is to be sure that the dock has tall pilings. An
adequate piling height is six feet above the gunwale. Much higher
than this is not practical, but if the pilings are only a few feet
higher than the gunwale at high tide, then one way or another the
boat has to be gotten away from the dock. Narrow slips are another
problem. If a dock slip is too narrow, then there's no chance of
keeping it off the pilings with the rise and fall of storm surge.
The boat is likely to be battered by it's neighbors. Boats docked
in tightly packed marinas, even if well-sheltered, need to be moved
to better locations. If the boat can't be moored away from the pilings,
count on it being destroyed.
Coco Plum Experience This private marina at the south end
of Coral Gables gave us an excellent lesson in hurricane protection
in the aftermath of Andrew. Most of the boats in all the marinas
to the north and south of Coco Plum were destroyed, even though
all these marinas directly front Biscayne Bay. And yet, incredibly,
not one boat at Coco Plum was lost, and only a few had significant
what distinguished this marina from all others? First, the entrance
channel to the marina has a sharp dog leg that greatly reduced wave
action. Next, the marina was protected by a buffer zone of dense
mangroves. But just as important, the concrete docks at the marina
have very wide slips with heavy, tall pilings. This allowed boat
owners to tie their boats well off the docks. Even with a 10' storm
surge, not one boat came down on the pilings, and hence none were
lost. Whereas at Diner Key, Matheson Hammock and Black Point, nearly
all the boats were lost because all had narrow slips and inadequate
pilings. The lesson for boat owners with boats in narrow slips is
that your chance for survival is very slim indeed.
Its no longer legal for marina owners to force boat owners to leave
in the event of a storm. However, many of the marinas on the east
coast are quite vulnerable. Consider these points to determine whether
to remain in a marina. (1) Slip width should be minimum 140% of
the beam of your boat. If your boat can't rise and fall 10' without
coming down on a piling, you need to move. (2) Piling height should
be 6' above highest gunwale point. (3) Check tidal zone of pilings;
ideally there should be no wastage. (5) If the marina has lumber
bolted to concrete instead of full-size, driven pilings, move. (6)
Try to make sure that the boat is tied facing into the wind of the
approaching storm, an easterly direction. (7) If your neighbor's
boat is not as well tied as yours, his boat will likely wreck yours.
(8) None of the marinas on the barrier islands, or fronting the
bays, are secure. Move your boat or loose it.
Another Location All throughout south Florida there are
lots of good refuges available. It just takes a little time seeking
them out. Consider finding a well-protected, inland canal with a
good dock. Don't bother with anything with substandard pilings.
Important considerations are how far inland you wish to go, and
the obstacles of getting there. Check when bridges will be closed
and locked down. New River traffic, for example, is organized into
"armadas," with certain specified periods for upriver
travel. Moving upriver can be a very time-consuming job. Be sure
you're prepared to meet the schedules. Plan your move well in advance.
pilings for the Bertram in background are too close and too
low. The sailboat in foreground didn't have any pilings at
all, just a few pieces of wood lagged to the sea wall. Good
pilings would have prevented this.
Docks Canals that are well away from the Intracoastal offer
some of the best protection, so long as it has good pilings. Fig.
4 shows what usually happens if the pilings are not well suited
to the boat. The best arrangement is to have one piling each, fore
and aft on the water side so that the boat sets between the dock
and outer pilings. However, if there is not adequate clearance,
they'll probably do more harm than good. Pilings like this will
not only tend to fend off break away boats, but help keep you off
the dock without having to cross-tie on a canal. If you're a homeowner
and your canal is wide enough, it costs about $2,000 with permits
to drive two wood pilings, and its well worth the cost.
tie to wooden docks, especially cleats attached to docks; they're
guaranteed to come loose. After hurricane Opal, virtually every
wooden dock we saw was damaged or destroyed and many pilings were
pulled out. You have almost no chance of survival tied to a wooden
dock. Moreover, pilings that are jetted in with water jets, instead
of being driven, have very little holding power. If you're using
cleats on concrete sea walls, make sure they're well attached. The
bases on Coconut and Royal Palm trees make good mooring posts in
winds up to 150 MPH. Beyond this, even the palms start coming down.
But make sure the palm is not too close to the water's edge.
and Lines Making the proper attachment to a cleat or a
piling is far more important than one might imagine. What's okay
for normal use often fails during the violence of a hurricane. You
should have an extra set of new, and slightly oversized storm lines
- about 1/4" larger than normal size. By all means, do not
depend on aged cordage. Remember that, although an older line may
look okay, it may be seriously weakened by ultraviolet or fungicidal
degradation that may not be visible. Use new lines for primaries
and the normal dock lines as backups or doubles.
doubling up lines, try to reduce dependency on a particular tie
up point. Any time you can double a line to a different point, do
it. Two lines tied to one piling or cleat are of no help if the
piling or cleat fails. Spread lines to as many different tie points
as possible. Consider that under high water conditions, your lines
will be angling downward as the water level rises.
tie to cleats on pilings. Lines tied to pilings should have a fair
lead off the curve of the piling (tangential) and should not be
cinched by the knot so that the line is pinched or pulled by the
knot. Take only two wraps around the piling, making sure that they
do not overlap. Cinch knots or hitches around the piling should
not be used as this pinches the rope. Remember that it is the friction
of the line around the piling that provides 98% of the holding power.
There will be very little pressure on the knot which merely keeps
the line from slipping. Do not use bowlines; instead, three simple
half-hitches around the standing end are more than adequate and
will minimize chafing. Then wrap the free end back around the piling
with hitches to keep it in place.
Chocks and Pulpits There is a right way and a wrong way
to attach a line to a cleat. Cleats can be troublesome because rope
can get pinched and abraded if not tied right. We recommend that
only lines with properly made eye splices be attached to cleats.
Put the eye through the center hole of the cleat and fold it over.
If you have to use hitches, make sure the line leads off the base
as fair as possible with minimal potential for chaffing against
rule for cleats is, the larger the better; the smaller the cleat,
the more it pinches. Nowadays, mooring cleats seem to be getting
smaller and more poorly installed. Now is the time to take a look
at how they're attached. Do they have adequate back up plates on
the under side? Aluminum or fiberglass blanks make for the best
back up plates. Plywood doublers will crush and allow the cleat
go loose. Back up plates should be as large as practical, preferably
1.5X the length of the cleat and 1X length wide. If your bow cleats
are too small, and don't have adequate back ups, seriously consider
studies of Hurricane Opal revealed that large numbers of boats broke
loose from anchorages and docks because of lines cutting on various
areas of bow pulpits. A lot of pulpits have a sharp edges on the
underside that can very quickly slice through a line. The motion
of a boat in a storm is far more violent than one might imagine.
A pitching pulpit can snag a dock line or anchor rode. If the bottom
edges of your pulpit are sharp, its a good idea to have the edges
rounded over as much as possible.
chafe protection, we recommend that stiff plastic hose, such as
old garden hose, be slid over the end of the line. Plastic hose
is slippery and resists abrasion better. The hose should not be
slit down the middle because the chances of it coming off are very
high. Drill a hole in each end of the hose and tie it to the mooring
lines with nylon string, running the string through the laid line
to prevent movement. Don't use rags for chafe protection, they won't
do the job.
chocks tend to be particularly troublesome because they're usually
poorly designed, tending more to damage the line than protect it.
There are several types of mooring chocks that are extremely bad
this way, having sharp corners. If your chocks are like this, get
them replaced and make sure that they have good back up plates below.
Many are just screwed on and won't hold. Through bolting into an
aluminum back up plate is best. Its better not use a chock than
one that's guaranteed to cut the line.
in particular have notoriously small, badly shaped and poorly placed
cleats and chocks. They are often placed in a cluttered spot on
the bow with other equipment that will cut the lines. This is one
of the reasons why so many sail boats break loose. If this describes
your boat, consider upgrading if you want your boat to survive a
Anything that increases the windage above the superstructure is
called tophamper. Virtually all canvass, tops and sails and enclosures
should be removed from the vessel. If you can get these off the
boat completely, so much the better. Cabins stuffed full of sails
and canvass have hampered many a salvage operation. Outriggers should
be removed from the boat, as well as antennas, particularly if they're
on a tower. Don't hesitate to cut antenna wires, if necessary, to
get them off. For sailboats with a lot of external halyards, we
recommend that you cut the end and pull them down; they dramatically
increase wind resistance aloft. Its also a good idea to remove the
boom, if you can, and lash it down ashore.
all pedestal seats to be sure that they are securely locked. All
exterior cushions, even if secured with snaps, should be removed
and stored inside. For loose deck furniture, if you can't remove
it, group it together in a corner and thoroughly lash it to railings.
Tape up all exposed cabinets and drawers. If you have a Plexiglas
bridge windscreen, unscrew it and store it below.
boats survived the eye of Andrew, despite fronting directly
on Biscayne Bay with a 10' storm surge, by a combination of
cross-tying and anchors. The sail boat had 3 anchors out that
saved it when the forward mooring lines broke.
Towers A number of sport fishermen with tuna or marlin
towers were literally capsized by wind. When the vessel starts to
heel over, the Bimini or tower top then starts to catch the wind.
Once this happens, it will either capsize or be torn away from the
moorings. If a strong category two or higher storm is approaching,
we recommend that a Bimini strung on a tower be removed since it
won't survive anyway. This will greatly reduce the chance of capsizing.
Remove everything that will be wind or water damaged.
Protection Some yachts sank because the boats heeled over
so far that the hull side ventilators went underwater. But also
remember that 150 MPH winds eliminate any distinction between sea
and sky. Wind-driven water is going to go right into the engine
room vents. If the engine room hull side vents are small enough,
they can be taped up with duct tape. If the vent is larger, use
a thin piece of plywood and screw it directly into the vent cowl
or even the hull side if that's all that is available, and then
tape over the edges.
forget that on the reverse side of the storm, the boat may be hit
by winds from astern. If you don't want to take the chance of water
being driven up the exhaust and into your engines, then plugging
the pipes is the thing to do. Sailboats and gas engine boats can
use simple wood plugs. Sail boat owners absolutely should plug their
exhaust lines and close the sea water intake sea cocks. For larger
diesel exhausts, the inflatable balls available at most marine stores
are the best solution.
you have a generator under an open cockpit deck, cover it with sheet
plastic so it won't get wet. Close the water intake sea cock. If
you have the proper size bungs, stop up the exhaust outlet. Tape
over with duct tape the fuel and water tank vents on the side of
It should go without saying that all external electronics should
be removed. That includes those mounted in covered boxes. After
Andrew, we found shredded leaves inside closed, locked electronics
boxes. The wind force was so great that it bent the plastic doors,
creating gaps. Again, don't hesitate to cut wires and cables for
removal. The cost of reinstallation is far less than having to replace
costly electronics. If electronics inside boxes cannot be removed,
completely tape around the cabinet doors with duct tape to help
keep water out. Tape tightly over all instrument faces that can't
be removed, as well as switches and the like.
& Hatches One of the more amazing results of our survey
was how well window glass holds up even in the most extreme winds.
Less than 5% of all boats we looked at had broken window glass.
Plexiglas, on the other hand, fared poorly. However, wind-driven
rain is a serious problem that can find its way into the smallest
cracks. We also learned that most superstructures on motor yachts
are fairly weak. That means that wind stress often distorts superstructures
enough open up small gaps in window frames and between glass panels.
Also that the wind can set up some really heavy vibration that will
rattle sliding glass panels open. Be aware that wind pressures can
literally bow window glass and hatches, opening up gaps that you'd
never imagine possible. We've found shredded leaves inside boats
and couldn't imagine how it got there. We recommend that all windows
be locked and taped with duct tape. Tape all joints and
seams on both sliding and fixed window glass on the outside. If
you have window covers, leave them in place; they often help. Also
tape around all hatch covers and entrance doors.
the Interior We already mentioned how violent the motion
of the boat can get, so its wise to take the same precautions on
the interior. For example, in the galley clear out all elevated
cabinets where doors will open and contents spill out. Even tape
probably won't hold the doors shut. Put breakables in boxes down
low. Remove all heavy objects that will force doors open during
extreme rolling. Anything loose like televisions, bric-a-brac, lamps
and the like should be secured on the sole. Prepare for some serious
water leaks. Slide furniture away from windows. Raise venetian blinds
and take down drapes; they'll get wet for sure and if a window breaks,
they'll cause even more damage. Take up all carpets in lower quarters
and place on berths. Roll back or take up carpet in way of exterior
doors, then duct tape the door jambs when leaving the boat to keep
wind driven water out.
on berths in forward cabins in way of port holes and hatches should
be wedged up on end so that leaking won't soak them. Strip, pillows,
sheets and spreads and store in a safer place.
forget the refrigerator. Clean out all perishables and glass bottles
that will slide around and break. Make sure the door is firmly latched.
If you have an AC/DC reefer, make sure that is turned OFF so that
it won't drain the batteries.
the sea cocks for the heads and close them. Close or plug all sink
drains. Shut off all other sea cocks except for the main engines.
and stow shore power cords away. Electrical power will be lost anyway
and leaving it plugged in will only result in the loss of the cord.
Turn off all DC circuit breakers except the main and bilge
pumps. Then make sure that all pumps are working and the batteries
are fully charged.
Boats: Owners often strip off all sails and canvass and
stuff it all down below. Unfortunately, if a boat fills partly up
with water, this creates a terrible problem getting these materials
out of a flooded cabin. If you can, get all loose sails off the
boat. If you take the furling genoa down, again, don't stuff it
in the cabin. Tie it to a tree or something, or take it home. The
cabin areas should be kept as free as possible to tend to an emergency
hosing down the interior of your boat and then letting it sit for
a couple days. That's what the inside of your boat is likely to
look like when you finally get to it, many days later. Your boat
will leak in ways you never imagined impossible. All that stuff
packed into lockers needs to be removed. The easiest way to deal
with it is to stow it all in heavy trash bags and seal the ends
tight. Then stow them tightly in a high corner somewhere.
vent cowls and heavily tape over the openings.
all the bunk and dinette cushions, stand them edgewise and wedge
them in place such as around the dinette or a quarter berth.
all sink and head sea cocks. Check to be sure that cockpit scuppers
are clear. Loch the wheel or lash tiller in the centered position,
not to one side. The Bimini top should be removed from the boat,
frame and all. Don't try to lash it down because the wind will tear
it free. Lash it down ashore. Remove all equipment attached to the
lifelines or pulpits.
tape over all windows, ports and hatches around the base. When leaving
the boat, tape over the companionway hatch joints.
Cruisers If you have an open cockpit express cruiser, take
down the top frame because you'll loose it anyway; if the frame
gets loose it will do great damage. Dismantle the top, remove the
cover, and stow the frame on the cockpit deck. If you have a canvass
instrument cover, it won't help. Instead cover instruments and switches
with duct tape, applying in a shingling fashion. Just remember to
get it off soon after the storm. Remove electronics and tape up
any open holes in the dash. Tape all switches and the ends of the
cable connectors. If you have a generator, cover it with plastic.
Next, duct tape the gaps of all hatches in the cockpit deck. This
will help prevent water from getting in the engines, particularly
the generator. Then, make sure the deck scuppers are clear. Tightly
lash fixed, folding swim ladders. Remove all antennas, don't just
fold them down. If there are electric panels in the cockpit, tape
around the doors. Remove all loose deck equipment such as fender
racks, life rafts and anchors. Before leaving the boat, tape over
the companionway door jamb. If you have a gas boat, we recommend
that you shut off the fuel valves to all engines, especially the
valve at the tanks.
See also Hurricane
the Author: Dave Pascoe is a Ft.
Lauderdale, NAMS Certified Marine Surveyor with 30 years experience
in dealing with marine catastrophes, starting with Hurricane Agnes
in 1968. Most recently he has worked Hurricanes Andrew, Erin,
Opal, Hugo and Marilyn. The information contained in this article
is the result of his studies of the effects of these storms on
boats of all types, and in a variety of geographic locations.
(He currently resides in Destin, Florida.)
First posted in spring
1996 at marinesurvey.com.
Copyright 1996 - 2005 D.H. Pascoe & Co., Inc.