Tubes in the water under way. Drag or stability?

[DM]

Originally Posted by JIY

At speed, the hull shape is certainly the important factor in achieving stability, but the tubes still provide dampening and roll limitation during rougher sea crossings, even if they are clear of the water.

Spot on!

Originally Posted by JIY

The drawback of tubes touching the water, other than drag, is that the flanges can take a bit of a beating, with possible long term wear damage.

.......whereas the drawback of them NOT touching is that, at speed, with lots of up trim, you can get tube bounce which is often confused with chine walking.


DM

[Matt]

Is that what happens when scratcher runs and his manbreasts start bouncing?

Originally Posted by davidmanning

you can get tube bounce which is often confused with chine walking.

[DM]

Originally Posted by MadMat

when scratcher runs

Unlikely scenario.

DM

[Rogue Wave]

Originally Posted by davidmanning

.

I've been thinking about having a whip round for the recent forum hardboat converts. We need to buy them a mirror, a bell and a nice piece of cuttlebone.

DM

i THINK THAT'S A VERY CHEEP DIG AT HARDBOATERS!

[Rogue Wave]

i 'd be driving hardbotes a b it at the moment andthey are definitely not as comfortable a ride in te rough so I think the toobs make for a softer ride although a slower one

[Hugh Jardon]

if at speed the toobs are touching the water then it must be a tricky rib to turn and lean over?

mine are clear of the water at rest and well clear at speed unless doing tight turns and then they dig in nicely until i get the prop out of the water!

mine and mollers sit at similar heights out of the water but my boat sits with a slight lean due to a few things being fitted to the rhs to balance it all up nicely!

[Cookee]

Originally Posted by pop

the way i understand it is the sponson should just touch the water when at rest to optimize stability but when underway should be clear of the water so as not to make the tubes ware as they get dragged through the water at 45knots.

couldn't have put it better myself!

[PeterR]

When i first took delivery of my new Shakespeare 6.2 At top speed it did chine walk badly For reasons Known to many the tubes were removed and replaced by Henshaws.At my request i had the tubes fitted with a longer overhang at the sturn as well as the bow .The bow for more impact cushioning as they were not enough originaly far enough overhanging and the stern just for the kids to have something to climb up on after knee boarding(and to make it look bigger)The result its over 6.6 metres doesnt chine walk still does over 54 mph with one on board and 50ltr fuel and 25kg in bow locker .It is fast accellarating and will turn well at high speeds