Flotation Compartment Experience Needed

[Mark Gudschinsky]

We have a Skipjack under construction for Capitan Laura who is eight years old. The construction consultant (Dad) has decided his little girl needs to have an unsinkable boat. So flotation chambers will be included in the list of modifications to the plans.

Which leads us to the question. Should the flotation chambers be sealed tight with nothing ever to get in or out, or should there be inspection ports and drains to make sure all remain dry?

Sealed tight has the advantage of there being no chance for a plug or port to be left open which would defeat the intent.

Ports and drains have the advantage of improved upkeep and inspection.

Ideas, opinions, experiences?

[ChrisObee]

Which leads us to the question. Should the flotation chambers be sealed tight with nothing ever to get in or out' date=' or should there be inspection ports and drains to make sure all remain dry?

Ideas, opinions, experiences?[/quote']

floatation chambers should be filled with USCG approved foam. With foam you don't have to worry about a puncture in the floatation compartment. Once filled with foam they can be sealed never to be seen again.

[Frank Hagan]

Well, we should make sure the electrical is to ABYC standards also. And Mark, remember that the USCG now requires manufacturers to provide a warranty on their boats ...

This is a Skipjack, right?

Wood floats. So the boat has flotation already. It would only sink if the amount of non-floating stuff you have is heavier than the natural flotation, and it somehow stayed in the boat when it tipped over. (My experience in small boats is that EVERYTHING ends up in the water.)

Providing extra flotation might be a good idea, but I wouldn't stress too much about how its done. Empty 2 liter bottles, air spaces, or my favorite, inexpensive styrofoam, work well. The main thing to be concerned about with plywood boats is leaving a place where water can collect and get next to the wood, and rot it out. So provide air circulation, drains, etc.

I put some styrofoam behind the seat backs in the Weekender, and I remember quite a bit of conversation about if that would just make it harder to right if it turtled. (Has anyone ever turtled a Weekender? I don't remember hearing of one.) I bought 2" thick slabs of it at a plastics place that supplies it for floating docks. It lasts 10+ years in that environment. But the main thing is I left the area open to the lazarrette so that there was air circulation around the foam.

I don't like the pour-in-place foam in plywood boats. Always seem to rot along the top of the foam, where water collects and sits. If you have a bubble in it, with air next to the hull, condensation forms inside the air pocket and rots out the plywood.

[Tom Lathrop]

A small boat should have enough positive flotation to keep the crew afloat (not including life jackets) in the event of a capsize. In a small wood boat, usually some waterproof foam might be required to add to the natural buoyancy of the wood achieve this level of safety.

The CG does have a number of pounds of positive buoyancy required in store bought boats to effect this level of flotation but I don't remember it. The Cg requirement is in addition to any sealed air tanks.

I would NEVER fill flotation tanks with foam. First, this foam is not waterproof and will soak up any water that happens to get inside the tank. Second, that water can cause rot and cannot be gotten out short of demolishing the tank. Third, the water taken up can add a lot of weight. Fourth, Since the tank should be made waterproof anyway, why would you want to fill it with foam. Fifth, with access ports, a flotation tank can be used as storage space for things you don't want to get wet. Finally, installing expanding foam in a tank is tricky business since it can easily deform the tank if not actually blow it apart.

When I need to add solid flotation, I glue in some blocks of the 2" thick waterproof blue styrofoam available at local building suppliers. Space should be provided for ventilation around the foam unless it is sealed to the inside surface.

All tanks should be provided with drain ports at the lowest point in case some water does find its way in. Access ports should be left open when the boat is in dry storage.

Some fiberglass racing sailboat builders used to fill spaces with expanding foam but after those boats became uncompetive because of weight gain, they stopped doing that. Some have needed to pour solvent into the spaces to melt the foam but some residue always remains along with some of the added weight.

[Tom Lathrop]

Ray,

It seems that I am in complete agreement with you and my boats are build in the same manner. That is, with adequate "positive" buoyancy from the boat itself and added waterproof foam for ultimate safety and air chambers for quick recovery.

I would do this whether the CG requires it or not.

[ChrisObee]

Quite the can of worms I opened. I'm sorry I used the USCG word. I did not mean to imply that you must build to their standards just that the foam that they specify is an excellent source of fool proof positive buoyancy.

[Stump]

Actually, it was fairly tame...(whatever you do don't ask Ray about ballast...wink, wink, nod, nod.) But truthfully, the amount of very excellent information from Ray and Tom and Frank and Capt. Jake and Bob and Oyster and Charlie, and Greg and Berry and Steve and Mike and I think I have opened a can of worms here, :oops: among ALL the other wonderful contributors and I am so sorry if I didn't name you it is only my poor faulty memory, is immense. Don't be shy :wink:

[Guest]

Well, well, well, let me add just two lines, if possible. :wink: There is way too much emphasis placed on foam and its safety net. While there are advantages to using it, there are huge disadvantages to it also, creating problems with your boat. But in small boat applications, a prudent mariner will not rely upon one single item to save your butt. Practice dumping your butt, in shallow water, yes even kids that may end up in a potential situation, so there will be no panic while dealing with the problems. A boat, awash on the surface, with people frailing away, in the wrong conditions, can be just as bad with or without foam.

[Guest]

Pardon me, but gotta clear something up here. :shock: I did not tell the fine people to forgo foam. In the original post, it states " Flotation chambers" Done right, there is a lot to be said for air chambers, with marginal foam, as has also been commented on here. Heaven knows when even a whale will punture the small craft, hitting it right about the sealed compartment, or the rock on the beach trick. Part of my post was addressed to others commenting here, not knowing the exact location, too. People will just over foam, filling without dealing with proper care and sealing of the compartments, causing many problems with dampness that occurs in a semi voided greenhouse. But kids, that have a boat capsize on them, should have previous experience with the experiences, such as will be done in most juvenile sailing schools.

[Kidd]

Foam, no foam, either or both. Training and supervision are the key with kids. I agree with the teach them how to right the boat in shallow water. Make them do it over and over.

[Barry Pyeatt]

Mark,

I would recommend that you go ahead and advise your client that sealed air chambers in the bow and stern would be an advantage to the seaworthyness of her fine craft. I would advise her to get a couple of the fine plastic access hatches that screw in and lock it up to protect any valuables that she would want to protect on her voyages. It is a good area to keep valuables and treasures that might otherwise get lost if the craft did capsize.

In the interests of increased "peace of mind" to the skipper and her concerned relatives, I would also attach a full size section of closed cell foam (either the Pink Panther type or blue board) below the seats where it is protected and out of the way. I would attach it with straps of Velcro so that it can be removed when desired such as when it is stored for the Winter season.

A good source for the access hatches is the Boat Building Store at Duckworks.com The have many quality products that the skipper may wish to consider to equip her craft. I recommend them highly as the are affordable and of good quality. http://www.duckworksmagazine.com/store/hardware/deckplates.htm

Another product that I would recommend for both your young skippers boats as well as your own would be the following: http://www.duckworksmagazine.com/store/hardware/misc.htm#step

This is a very handy addition to a well constructed seaworthy craft and one that could make a difference in reboarding the craft easily and safely if it gets swamped or overturns. :wink: Certainly makes getting back over the rail a bit easier and gives a person in the water something to grab onto and hold.

[Mark Gudschinsky]

Well this stirred up quite a few good opinions.

We are going with Bow and stern air chambers, as well as one on each side similar to Weekender seat backs. I want this thing to bob like a cork.

I have been convinced to build in inspection ports and drains for the longevity of the craft. I may also include ridged foam to counter the possibility that kids playing pirate might open a port to stash some booty rendering the floatation chamber useless. I'll have to figure how best to combine the two.

We actually have done some blowdown and man over board drills. We will get more elaborate and make the crew show there worth in "emergencies" this summer. We even did swamping practice with Swimmer (an 8' Amphora.) Like all of the knock down / swamping incidences I've read with the Stevenson's crafts self rescue was basically out of the question.

Alexander was able to board, and the boat floated upright and awash, but in mostly calm water he was unable to bail without dipping the rail under water. After I scoped out about five gallons worth he was able to bail successfully, but even an eight foot dingy hold a tiring amount of water. After ten hard minutes of bailing with the boat still 2/3 full he rowed over to our power boat and using his head borrowed our portable bilge pump to finish the task while he went swimming.

The idea of the boarding handels is also important. When Alexander first took Swimmer to the lake, one of his tests was to see if he could get back into the boat in deeper water. He couldn't do it! That weekend, we installed the boarding step that was in the plans. Then he could board easily.

So, Laura's Skipjack will also get a trasom mounted boarding ladder.

This is especially important in cold water areas such as we sail in. The cold quickly saps your strength and may prevent reboarding. Also for a bit of fun next time you go sailing try jumping overboard and getting back in un assisted. It can be pretty tough especially if you have a nicely polished finish on your boat.

[Frank Hagan]

Hey, water where I am is actually pretty cold ... I'm north of Pt. Dume on what is really the central Californian coast, and we get water temps in the high 50's, and rarely into the mid-60's. Go further south and it gets a bit warmer.

I've heard the Gulf Stream warms the water on the eastern seaboard as far north as the Cape in MA. People from NJ are always surprised at how cold our ocean is compared to "home". I know that's not the 40 degree water you get up in Alaska, but anyone who is going to spend any time in our water wears a wetsuit. Anyone on a Laser wears a wetsuit as well. I was looking for the hypothermia charts, and couldn't find them. But its a serious concern in colder waters.

[Tom Lathrop]

I don't think that this business of flotation in a small capsizeable boat has been overdone at all. However, there are cases where having a lot of flotation has caused problems.

Let me explain. I started out sailing in the Windmill class and raced extensively as well as teaching sailing and running races for almost 40 years. Anyone who races small boats actively will have experience with capsizes. If they don't, they are sailing too conservatively and definitely not winning very often.

My first Windmill, like all the rest at that time, had no flotation at all other than the wood itself. It was possible for experienced sailors to right the boat and bail it out but it was not easy. After adding large air tanks the full length of each side, the boat could then be righted with no more water than could then be sailed out through the automatic bailers. This takes some skill to do effectively also.

Now, the problem with flotation is that capsizes usually occur when there is a lot of wind. If the sailors loose contact with the boat, it can easily blow away faster than they can swim. The high degree of flotation needed to make recovery rapid enough to continue racing also makes the boat float high enough to make a good sail. We all quickly learned to hold on to a sheet or something so that we stayed with the boat.

As an aside to the current uproar about requiring wearing lifejackets at all times, I did not always wear mine when racing. However, I never capsized when I was not wearing one. The answer is obviously to use common sense, observe the conditions and have a lifejacket on when it is either windy or cold.

The practice of forcing all learning sailors to learn to right a capsized boat has been part of all classes that I have been involved with. No one should venture out in a boat that capsizes readily unless they have gone through the righting and recovery experience in a similar boat.

I've no experience with a Weekender so can't say whether it capsizes easily and, if so, how easy it is to recover. I do know that a lightweight crew on a large boat can make recovery more of a problem. Also boats without any added flotation will be more stable either on the side or upside down as will boats with added flotation low in the boat (double bottoms). As much as practical, added flotation should be placed high and as near the sides as possible.

A little long but I get windy at times too. :roll:

[JeffM]

I'm hoping to go adventuring with young children late this summer IF I can get my cs20 far enough along to sail it by then. I like Ray's club idea. As far as floatation in my boat goes, it has 6 (albeit integral) chambers, all with store-bought gasketed hatches. Those for the forepeak and lazarette lockers are on or near the centerline. Sounds pretty safe to me. But maybe I'll throw a few empty 2 liter soda bottles in each locker for good measure. I'm gonna get me one of those duckworks boarding ladders also. I'll bet it sees some non-emergency use!