Emergency Flotation and Reserve Buoyancy
If your boat becomes swamped a distance from shore, you could die from hypothermia in as little as 15 minutes, even on a warm sunny day. The chart below from the U.S. Coast Guard shows the effects of hypothermia and how quickly it can effect you.
While the PDRacer is a very stable boat, there are many scenarios which you can get knocked over. Being able to self rescue your sailboat is a very important feature and could save your life. Airboxes provide buoyancy in ways which allow you to right your hull, reboard her and bail out the remaining water so you can self-recover your boat from being swamped or capsized.
|32.5||under 15 min||15 to 45 min|
|32.5 to 40||15 to 30 min||30 to 90 min|
|40 to 50||30 to 60 min||1 to 3 hrs|
|50 to 60||1 to 2 hrs||1 to 6 hrs|
|60 to 70||2 to 7 hrs||2 to 40 hrs|
|70 to 80||2 to 12 hrs||3 hrs to indefinite|
Kids and Hypothermia
Kids are at a greater risk of hypothermia because they have smaller bodies, less mass, and loose body heat quicker. If you take kids sailing with you, you really need to be absolutely sure that you can quickly recover your boat when it becomes swamped.
Here are some methods used to provide emergency flotation in PDRacers:Worse Case Scenario
Recovering from a capsize
Airboxes at the ends
Airboxes on the sides
Using Pool Noodles (doesn't work)
Calculate Size Of Airboxes
Articles About Flotation
Filling Airboxes with Foam
A common first thought about air boxes is to fill them with foam, plastic bottles or other flotation. The purpose of the airbox itself is to be a sealed air box and to provide your flotation, so putting something inside of it is not going to make it perform any better. One negative effect of having foam inside your airbox is it can retain water and promote rot which you will have to fix later. So if it makes you feel better, then yes go ahead and put foam, bottles or whatever else you want inside your air boxes -- just realize the box itself is the most important part and they need to be built built strong and sealed.
Airboxes Both Sides
If you look at how to recover a duck in the essays above, you will see that you really only need one set of airboxes on one side of the boat, but ducks usually built with flotation chambers on both sides, so that way you have double protection. If you loose or break the airboxes on one side, you can flip your hull the other way
Being scared of knock downs and capsizing
If you have proper airboxes built into your duck, carry a bailer, and you practice recovering your boat, it becomes almost like capsizing an air mattress in your backyard swimming pool. Please practice knocking your boat over and recovering her. One way to practice is tie a long rope from a dock, row her to the end of the line and pull her over. If for some reason you can't recover her, simply swim back and pull the boat back with the line. Figure out what went wrong, and try again.
Mast Head Floats
One neat trick is to attach flotation of some type to your mast head. If your boat gets knocked over, the float will prevent the hull from going inverted. Many racing class sailboats use these so they recover from knock downs very quickly and get back into the race.
Strike Something and Damage Hull - Emergency Hole Repair
With a 3/8" bottom, it is very hard to puncture a hole in the bottom of your hull, but it is possible such as if you hit a stump or pointy rock. Sailors have been jury rigging repairs to their hulls ever since there were boats, here are some ways to repair those holes so you can sail back.
Stuff a rag in the hole - most of us carry some kind of rag or sponge to get rid of spray water. Just stuff the rag in the hold, and it will plug up good enough for the trip home.
Wrap something on the outside of the hull - Captain Cook struck the great barrier reef while discovering Australia. To fix the hole, he placed a sail over the hole (on the outside of the hull) and tied it in place. Its called fothering, that was plenty good enough to seal it, so he could sail to a beach and then repair the hole properly. Also Inuit build skin on frame kayaks, so basically the entire kayak hull is really just a frame with an animal skin to make the hull.
Sit on the hole - A buddy of mine was sailing on his favorite lake on a calm day. Then suddenly mother nature whipped up some strong winds. It was a man made lake, so previously there had been trees that were cut down, and unfortunately many stumps remained. Since the wind kicked up some waves, he was riding them trying to get back. He was going down one wave and suddenly CRACK! a 4" stump pierced all the way though the bottom of his hull. (his boat had a 1/4" plywood bottom). Thinking fast, it threw a boat cushion over the hole and told his wife to sit on it. She did and it plugged the hole! They sailed 5 miles back to the ramp, just like that.