SIBS naturally have hooked hulls?

[Projectile]

Here are some photos of my boat on it's trailer. I deflated the keel for some cleaning, and the shape that the hull took is shown in the attached photos. The transom is on the right in the first 2 and on the left in the last 2 pics.

Notice the sizeable hook in the hull. No wonder I need to inflate my keel beyond manufacturer's recommended 3.5 PSI to get rid of bow steering and ventilation. When I do, the hook disappears.

Is this what the hull in your boats does when the keel is deflated too?

[m chappelow]

Dont worry too much Its when you get a few years on her & she starts to get a saggy bottom instead : )

[jyasaki]

The keel (and air pressure therein) is an integral part of the structure. Just as the floor spreads the tubes apart, and the tube pressure tautens the floor across the beam and locates the transom.


jky

[Starovich]

Originally Posted by m chappelow

Dont worry too much Its when you get a few years on her & she starts to get a saggy bottom instead : )

still talking about the boat?

[Tony B]

Originally Posted by Projectile

..... No wonder I need to inflate my keel beyond manufacturer's recommended 3.5 PSI to get rid of bow steering and ventilation. When I do, the hook disappears.....

Double check your manufacturers recommendations. Usually the tubes are inflated at around 3 PSI. the keel at about 4.5 PSI and if you have an inflatable floor, it should be about 8 - 9 PSI. Of course, these PSI recommendations will vary from manufacturer to manufacturer.