To properly lay up a boat for hurricane season is a job that must be done by owner, his captain, a very trusted friend or be done under the supervision by local surveyor.
Screw jacks or fabricated cradle? Fabricated cradles are seldom designed and built for a specific boat so the arms seldom match up with strong points, like bulkheads or half bulkheads. The arms and pads often end up against just the relatively weak shell of the boat. Boat jumps around in the cradle as the tie down straps have stretched. Hull is cracked or punctured which necessitates an expensive repair. If the fabricated cradle is specifically designed to fit the boat, with support arms meeting strong points on the boat, and the boat is really well strapped down, it will be a superb method of minimizing the chance of damage to the boat in a hurricane.
Screw jacks are very suspect unless they are properly set up. They should be on plywood pads so they do not sink in soft rain soaked land. The stands must be tied together port and starboard, not by chains, but by re bar welded to the stands. The handles of the screw jacks must be wired so the jacks can not back off if the boat wiggles or vibrates.
There must be plenty of screw jacks. I would estimate one for every 8’ of WL length. As many as possible should be positioned so that the pad bears on a strong point, a bulkhead or half bulkhead.
Boats must be strapped down with the straps secured well aft of the bow, and forward of the stern in order to minimizing the boat capsizing. Securing straps to chain plates and cocpit winches is ideal as they are at wide points of the boat.
Straps must be strong and set up as tight as possible as in 2017 many boats straps were ineffective. They were not strong enough or not set up tight enough. Straps stretched and were ineffective.
Nanny cay has solved this problem as they are using straps with a breaking load of12,000 lbs. Obviously these straps will not stretch. Ask the yard what is the breaking strain of their steaps. Unless it is up close to 10,000 lbs they will probably stretch under load.
Straps must be secured to dead men well buried in the sand, sand screws, or strong bolts secured in the concrete where boats are on hard standing. When boats are on hard standing the tie down points may not match up as to where the straps should be attached to the boat. The tie downs to keep the boat from capsizing should be at or near the points of greatest beam, by the chain plates and back aft by the cocpit where they can be arrached to the sheet winches.
In contrast, if the yard is sand or dirt, sand screws can be driven in where ever they are needed.
It is worthy of note that in the 2017 disaster in Hurricane Alley, in Independent boat yard St Thomas, just about every boat fell over except one. As the hurricane approached the owner of one boat ran around the yard and found many unused screw jacks. He fitted them between the ones installed by the yard. It was said after the hurricane that the boat was not double jacked, it was triple jacked!. He also doubled up on tie downs set up bar tight. The time and effort was well spent as the boat was about the only one in the yard that was standing upright when the hurricane passed.
In Puerto del Rey in the hauling facility the boats are well tied down and survived Irma and Maria with little loss. But there is a repair facility that hauls, paints, repairs and re launches. The boats are not tied down for hurricane season. When Irma approached the rushed arround tieing boats down in such a fashion they felt would mean the boats would survive without being blown out of the cradle .
The last boat they secured was a 38' fin keeled sloop. Once Irma passed the staff rushed to the yard all was well except the 38' boat. The jacks had not been well secured together nor wired so they could not unwind.
All the jacks had blown away, but she was so well strapped down that she was standing there on her keel held upright by tight straps. Unfortunately no one took a picture!!!!1 they were too busy getting jacks under her.
The modern racing boats with a deep fin keels and deep fin rudders, the hull stands so high that it is impossible to tie it down with either screw jacks or in a cradle to survive a tropical storm much less a full hurricane. The keel and rudder must be in a well. They are usually so deep it is impossible to just did a ditch in the sand and set the keel and rudder in the ditch. If the sides of the ditch start to collapse, the boat will be firmly planted like a big tree. Digging out a tree a tree without damaging the roots, or a planted boat, without damaging the boat is expensive. The really good yards that store boats of this type, have concrete lined trenches. The rudder and keel are in the trench, the boat is chocked high enough so that if the area floods the boat will be above water level and not float. The trench should have some diesel, kerosene paraffin poured into the trench so mosquitos will not breed in the rain water that will tend to accumulate in the trench. To keep the concrete lined trench from gradually filling up with rain water, the bottom should not be concreted but rather left bare earth so rain water will hopefully gradually seeps out into the dirt or sand.
For a normal full keeled cruising boat whose draft is not too great, some yards get out a JCB/back hoe, dig a hole for the keel and rudder, place tires around the hole and lower the boat on to the tires and strap the boat down to dead men buried in the sand or sand screws. This system has worked well except where the yard is on a flood plain.
Where the yard has been on a flood plain, and boats have been placed with their keels and rudder in a trench and chocked on tires, it has been disastrous as some boats floated half out of their hole, the tires floated away, wind combined with flood ended up causing considerable damage. I had to settle an insurance claim as the result of the above scenario.
Ventilation, a real problem, leave boat semi open well ventilated all is well except rain!!!! Close up completely and when crew returns in November to re commission, boat is full of mildew.B
Solution good BIG dorade ventilators. kevinpls insert link here. On modern boats the dorade ventilators if they exist are too small too low. On Iolaire 46' yawl we had five BIG dorade ventilators. From 79 thru 94 she was left in the Caribbean, un occupied, someone visiting only occasionally to pump bilge. From 96 until she was sold in 2009 she was left during the winter for months at a time, no one on board yet neither in the Caribbean nor in Nortern Europe did we have any problem with mildew.
Simarly L'll Iolaire, 28' yawl, had two BIG dorade ventilators. She was left unoccupied during hurricane season from 1995 to 2004 when she was done in in the closing hours of Ivan by a 50' catamaran dragging down on her. We never had a problem with mildew.
Hurricane season is also rainy season.
It is essential to pull a speed gauge, or fathometer or disconnect a sea cock low down in the bilge to make sure that any rainwater that gets into the boat will drain out. You may think you have left the boat in a water tight rain proof condition, but hurricane season is also rainy season. No hurricane may arrive but I have heard stories numerous times of owners returning to find a couple of feet of water in the boat and an expensive repair job. When a transducer is pulled, or sea cock disconnected it is essential in the main companionway to tape a big warning note of what seacock should be shut , or transducer/speed gauge re installed before the boat is launched.
Also on the outside of the hull where the transducer was pulled or sea cock disconnected, an X with small stainless or bronze rod should be taped over the opening so a rat can not get into the boat and do damage. I have heard of two boats where a rat got in thru the tranducer hole and did massive damage to the interior furnishings and electrical system of the boat before the rat died!!!!!
Also check very carefully the wooden structures near your boat and for termite tracks. My nephew, Morgan MacDonald, a very experience shipwright who has spent most of his life in the eastern Caribbean, reported the case of a boat were termites from a near by building got into the interior of the boat and had a five month feast. The repair job was very expensive.
Rig in or out? If it is at all possible the rig should come out. The following table shows the force exerted on a 60' mast and rigging accross a range of wind speeds. With these loads exerted on the beam will the boat stay in the cradle?
kevin can you pls copy this and send to me so I can ask scott if he can supply the kts equivalent to mph
|Windspeed mph/kts||Estimated Side Force On 60' Mast and Rigging lbs|
|20 / 17||80|
|40 / 35||320|
|60 / 52||720|
|80 / 70||1280|
|100 / 87||2000|
|120 / 104||2875|
|180 / 157||6470|
If the rig is left in, send all halyards except the main halyard up to the mast head. Secure the main halyard to the gooseneck and set it up tight. Do not secure it to a pad eye on deck. I talked to a skipper who had secured his genoa halyard to a strong pad eye on deck that had a backing block. In Marilyn, the wind load on the halyard was so great that it pulled the pad eye and backing block out of the deck. This left a big hole that collected a large quantity of rain water that did damage below decks.
also this table as mph /kts table can no be correct
Load on the Ends of a 1/4" Wire
Secured to a pad eye
Looking at the figures, the loads induced, if the mast is left in all halyards except the main halyard should be pulled to the top of the mast. The main halyard shacled to the gooseneck not to a pad eye that might pull out.
Remember, there is a big disclaimer that should go with all of this. It is highly dependent on the drag coefficient of each component and I have lumped a few shapes together and made some estimates to get in the ballpark. Also the “boat” dimensions are pretty generic. A boat like IOLAIRE will be a lot different than similar length IRC style boat.
To minimize windage, everything possible should be removed from on deck, dodgers, weather cloths, solar panels etc.
If you are leaving your boat laid up out of the water during hurricane season, you personally should make sure that your boat is properly laid up as described above. If you must leave before the boat is laid up it is essential you give to the yard instructions as to how you want your boat laid up. Do not rely on the yard to properly do the job.
Hire a local yacht surveyor to check that the yard has done everything on your list. Give the surveyor a copy of the lay up instructions so he can check the list when the yard reports to you that the boats is properly laid up. The surveyor can check the boat and verify the yard has properly followed the lay up instruction. If they have not completed the jobs to the surveyors satisfaction the surveyor can chase the yard to make sure all is done as you desired.