True Air Draft

[ethanbarnett]

Presuming an ordinarily stocked 29S with the mast down what is the approximate air draft? On our brochures it states 9’11” but what are the parameters of that measurement? I ask as we are looking at properties that may put us behind overpasses at 9’3” at mht. The edge of the hull sits approx 8” below the waterline.

 

[Kevin Lamont]

Presuming an ordinarily stocked 29S with the mast down what is the approximate air draft? On our brochures it states 9’11” but what are the parameters of that measurement? I ask as we are looking at properties that may put us behind overpasses at 9’3” at mht. The edge of the hull sits approx 8” below the waterline.

Hello,

We measure the height of the boat while sitting in the water with full of fuel, full of water and light on gear. Start from the water to the highest point on the boat. Hope this clarify's things for you.

Thank you,
Kevin Lamont

 

[ethanbarnett]

Well I finally put down the mast to properly measure her. Our findings show 9’ 1 to 2. I guess my wife's clothes lower us beyond the factory’s number of 9’11”.

 

[Mr. Ed]

In case anybody is curious and has an R31S...

I measured my R31S the other day, and the air draft with everything up (including VHF antenna) is exactly 17' 0". With the antenna down and the radar tower still up, it's 13' 6" to the top of the anchor light. Full fuel tank, full water tank, empty holding tank, and moderate amount of miscellaneous junk stowed away.

 

[JeffRad54]

Presuming an ordinarily stocked 29S with the mast down what is the approximate air draft? On our brochures it states 9’11” but what are the parameters of that measurement? I ask as we are looking at properties that may put us behind overpasses at 9’3” at mht. The edge of the hull sits approx 8” below the waterline.

Hello,

We measure the height of the boat while sitting in the water with full of fuel, full of water and light on gear. Start from the water to the highest point on the boat. Hope this clarify's things for you.

Thank you,
Kevin Lamont

Important note. Your Air Draft will vary according to the salinity of the water. Fresh is lower, salt is higher, brackish is in-between.

Jeff Radwill

 

[Sharron]

Cutwater 30CB - appears to need 18 ft or > for bridge clearance. Anyone know for sure?

 

[JeffRad54]

Draft varies according to weight of the boat and salinity of the water. There is no "true" number.
As another said, measure it yourself. Measure twice. Fully laden, and again with empty water and waste tanks and minimal fuel on board. Personal gear will not make that much of a difference, unless you carry a lot of gold.

This will at least give you a range of draft for your boat. If you Google 'effect of salinity on boat draft' or something like that, you will probably find a formula to use. Perhaps Googling Plimsol Line will give good results as well.

Remember also, that as your air draft decreases, your draft increases, and vice versa. It's typically a matter of inches, but those inches can matter.

Best of luck,

Jeff Radwill

 

[bill46]

I like minimum 18' for my 31CB.
Bent mast and wiped out light at 17'.
Did not know when bought.
Added one foot chain extensions to front guys to lay mast back about 30 degrees to get down below 17' for 4 bridges between by home dock and the ICW.
Always stop at marina after last bridge to raise or lower. Tip well so dockhands scramble to help!