Bulbous bows

[OrangeQuest]

If FG's hull was designed to be semi-displacement then the bow should only have water going under the bulbous bows and none going over the top, or less and less going up the BBs as speed is increased. Other than the additional flotation the BBs offer at rest and displacement speeds they should also offer "lift" at some point to allow the hull to start to climb the bow wave. The design of the BBs right now is to cut through the water and provide zero lift or the lift is being cancelled by the water being pushed up the BBs. Need to stop the water from being lifted at the bow and push the bow up. One way would be to take out most all the upward angle on the BB. A more horizonal top surface on the BB would stop the water from being lifted upward so much. But the point is where the water starts being lifted, that needs to be changed like the red line of the picture of the BB that FG drawn so the bow starts above the waterline.

The chin needs to go upwards more, above the water line at the BB's bow and at the same time prevent water from being lifted at the point of the BB's bow.

[fallguy1000]

Ken has done an accurate assessment I'd say.

[glossieblack]

Saw this bulb setup in a marina today. I think it's similar to OQ's thinking?

There are spray rails a little above the scum line on the inside faces of the bulbs, but not on the outside.

[fallguy1000]

I kind of think I'm headed that way; eventually.

[mhd]

Any progress? Have you had chance to test the new shape?

[fallguy1000]

I made some good changes and two different prototypes; one per hull. One is all pos angles; the other one neg angle on the top.

Well, I had no skipper, but cranked it up to 5670 rpms.

If Tom reads this, wonder where the rev limiters kick in on Yamaha VMX SHO 90s? If it is 6000, then I can go up one?

Anyhow, not too much splash; I was delighted. No videos.

The following weekend; took Mom and brother on a 60 mile trip and broke the fairing on both and so now; not even sure which one is best and can't tell, but only 5 weeks of season left; so probably will pull late October and build them both like the one I like. Which is pos/pos and looks like the bow.

[TomW1]

Dan could not find where the rev limiter kicks in but since the top rpm's are listed as 6000 it will probably be 6300 to 6400. Glad you got the BB figured out. Tom

[Fuzz]

You really need a couple of friends to help you sea trail things. Having someone run the boat at different speeds while you watched from another boat would be a huge help. And if the testing could be filmed it would be even better. I know it is hard to get people together to make it happen but it would be worth it.

[OrangeQuest]

You really need a couple of friends to help you sea trail things. Having someone run the boat at different speeds while you watched from another boat would be a huge help. And if the testing could be filmed it would be even better. I know it is hard to get people together to make it happen but it would be worth it.

A drone would be the way to go and a local kid would want to do it just to ride in the boat with Fallguy. The drone operator would even have the drone. Fallguy gets a copy of the footage and the kid is limited on what he/she can do with the footage publicly.

Could get so much data on doing adjustments on a time frame so looking at the footage could see how the hulls are effected with what.

[Fuzz]

Yep that would work too, maybe even better. Not having a drone I never would have thought about one.