Re: The Physics of A Boating Accident.
 

I agree with Tres you have to understand theory of how a hull works and what trim and tab changes do.This way it is easier to make proper changes not try to remember to do this and this when the boat is doing that.Plus a traditional Vee bottom is total different than a stepped hull Try to turn a stepped like a traditional Vee and you are calling your insurance company or worse

Re: The Physics of A Boating Accident.
 

A very intersting thread and great to see communication as it does breed awareness.

I have of course a few observations; First, in determining the physics of a boat accident there are more often than not any absolutes. It is usually discovered a sequence of events transpired leading up to the incident determined to be an accident. This is why we always stress checks and teach situational awareness.

I too have read Dags book and know he wrote a fast boat course for the U.S. Coast Guard. There is a lot of information some of value some not for our performance applications. Some things in the book we do not support.

When you operate any craft at extremis you must be able to recognize when something isn't right and develop/teach yourself inherit instict to be aware, acknowldege the problem, and act to create a sloution all within seconds or you will find yourself in a very bad spot.

Re: The Physics of A Boating Accident.
 

Great point Brad. Another thing that we teach in diving is pertinent too. If you have a little problem, correct it quickly or stop. Don't let it go on and then have another little issue pop up, then another, and another until you have a REAL situation on your hands. In analyzing dive accidents and mishaps this is a common thread. A small anooyance occurs and you ignore it, then something else happens and your concentration is split again. By about the third "little" thing you are starting to be really distracted and mistakes can bite you hard at this point. Any further without stopping and fixing the issues simply puts you closer to disaster. Since boats are such complex machines there are all sorts of things to nag at you, add to that friends or family on the boat, weather issues, traffic, water conditions, etc. and you have a real potential for danger if distracted.

Re: The Physics of A Boating Accident.
 

ya, I have. Show me a boat test on a sport boat with a stern drive using a cleaver prop. It would be a terrible prop to use on a submerged Bravo ( Like what you were talking about) Again, a cleaver would be used on a lightweight sport boat, where the drive is set very high. "Typically" on an outboard. You might be confusing cleaver with stainless steel maybe. I'm not sure, but a cleaver has a flat trailing edge and extreme rake. Plus they have a different hub than traditional props. here is a quote straight from the mercury racing site on cleaver's:
"Mercury Racing produces a variety of cleaver style propellers for small 30 hp outboards through 300 hp V6 engines. The cleaver style propeller, inspired from racing, are designed to run at the water surface for maximum efficiency. They work best on lightweight hulls which have natural bow lift. Three blade models for the 30 hp engines feature through hub exhaust. Larger three and four-blade models, available for V6 outboards, feature over hub exhaust."

"Propeller hub reliability is improved with the use of a new steel square-bore hub standard on all Mercury Racing Cleaver, Lightning E.T. and Chopper II propellers."

Not designed for Bravo's at all.

Re: The Physics of A Boating Accident.
 

good stuff here- I hope to take one TRES' classes someday, worthy investment IMHO.

Another nod for having your tabs /trim marked/ calibrated so you know what's really happening with your settings.

A digital, easily readble GPS is good for "enhanced feel" of settings at cruise and slower speeds where many of us spend the majority of our time. You can easily determine just how much trim past/near neutral is the sweet spot- increased trim will gain no results for a period and then then eventually rpm's will climb and speed will drop a few digits. I like (does not make me right though) the point where increasing the trim stops yielding benfits in incremental speed gains- seems like it would be more hull in water for evasive handling and avoiding the overtrimmed launch opportunity on wakes and waves.

Trying to go by the rooster is a mistake, as boats and setups vary. My 25' Daytona (cat) had an agressive x, liked trim barely above neutral and had minimal rooster (or perhaps it was "washed" by the tunnel wate/spray). My 28 Pantera also liked just one tick above neutral (though I always thought big single un- notched v's would want more) and the rooster was near non existant.

A friend on the lake has a 28 Daytona, Ilmors, agressive x, Imco's, 5 blades- he runs around throwing so much rooster that many perf boaters- myself included thought he was just a newb not knowing how to trim the boat.... Then I went and bought a mild powered 30' Daytona, mild X (shorties about to go on) and put 5 blades on- at neutral trim there is a good 3' of rooster... lesson learned on judging rooster.

That said- the one thing that I do suspect in many milder x perf boats is too much trim for conditions- which can be confirmed through methods above- sorry for the rambling- think there's some good stuff in there though.

Can't say enough about awareness though- peripheral vision, don't be trying to entertain and hold conversations while underway, maybe a good mate next to you just to announce overcoming traffic from their side. I go way wide of areas infested with tubers/boarders and waterbikes- their courses are just toooooo random. On nice days there will be rogue holes and wakes from Cruisers you can't even see cause they are around the corner now- just slow down some so you have extra margin for WHEN you encounter them:D

Re: The Physics of A Boating Accident.
 

Very good thread. Lot's of good information.
In the original question, you were looking for anything to look for, not just driving
So I thought I would chime in.
Get a good feel for your boat, and LISTEN to your boat. If something sounds different or "funny" - better check it out right away.
About 10 years ago I took my then wife, and a buddy to Cedar Point for a weekend - he caught a room, and we camped on the boat. 1st season with the boat, '86 Baja 250 Force, 330/TRS. It was late in the season, and I had put numerous hours on it in the season, and had many years experience on Erie.
We had to leave for home on a Monday, and woke up to 5's out of the west (we were heading to Toledo).
After beating ourselves up for about 30 minutes, but still running ok, I'm noticing a strange noise, almost sounded like a bad ground on the stereo coming through the speakers, kind of a hum, keep hearing this for a few minutes, so I backed off and raised the hatch. The motor didn't have thru-bolt offshore mounts, just bolted to the top of the stringer with lags. I had crushed the Starboard stringer, and the motor is listing down about a 1/2".
AND, I've got water coming in from the transom assy.
Bilge pump is keeping up, but I knew if I could keep the boat moving, the Transom won't have any water on it to come in.
Headed as quickly as reasonably possible to Put-In-Bay to tie up and get the boat in a sling.
Everything worked out alright, no-one was hurt, and no-one wound up wet (except from wave spray).
Got the boat slung up.
then came the fun of taking the Jet Express back to mainland. Getting picked up by a friend. Picking up my truck and trailer. Driving back to Miller's ferry to cross to the Island. unloading the boat onto the trailer, and just barely making the last ferry of the day with truck, trailer, and boat.
It really sucked sitting in my truck on the ferry, with my boat on a trailer behind me.
The decisions I made kept us safe, and everything worked out fine, but there certainly were flaws in what I did.
FIRST - My ex-wife was the only one of us three to don a life vest. I should have required this of my other passenger, and out of common sense for myself. I was in a frantic situation, and also was trying to keep the ex-wife calm - like everything is going to be fine. I forgot my first responsibility KEEP EVERYONE SAFE!
SECOND - I didn't contact the Coast Gaurd to let them know I was having trouble. Had the motor conked, or I started taking on more water than I could keep up with, they wouldn't have known to even look for us.

I'm sure someone else can chime in on other flaws in my actions, if you feel the need to feel free. If it keeps another boater safe, I'm all for it.

Sorry to be so long, but my simple point is LISTEN to your boat, and if something sounds wrong, something probably is wrong.

Re: The Physics of A Boating Accident.
 

I agree that with experience most of us can get a decent feel for our rig,s and how they handle and or react in most conditions.
Not that this isn't an informative thread and we should continue sharing our experiences, however.
If you really want to learn the physics of how your hull is reacting , where your trim should be , tabs etc as well as real life scenarios of how to quickly avoid an accident, pre- check drives ,hull and much much more.
Take the Tres Martin school, I learned more in two days than in all my 30 years on the water.

Re: The Physics of A Boating Accident.
 

Thanks! The only way to make a difference is to get right imformation! Everytime another acciddent on the water happens, all policies are in jepardy of a hike in price later down the road. Besides, the course is fun and very entertaining!

Re: The Physics of A Boating Accident.
 

I'm a pleasure boater not a racer or an expert but maybe this will be of some use to you.With the o/b's on my boat I could cruise at 100 but I can't read the water past 80 so I keep it to that and only in good water and in a straite line.This allows me to monitor and adjust for the conditions in front of me as they change.Since I don't race,unneccesary sharp high speed turns are something I don't do because it's a fast way to get into trouble with little or no chance of correction.However if I have to make the big turn I give and take gas from the motors thru the turn.This tells me the margine of error for the boat in THAT turn in THAT water at THAT speed.The boat is a 26 ft tunnel,not a v bottom.Good luck to all.

Re: The Physics of A Boating Accident.
 

REGGIE did a show on how to drive a vee hull back in 94, I think it was a good show, if I find the tape, maybe I can put it on here it was for nonstep hulls. I learned a lot from it and a throttleman ex world champ:D , not going to say who he is:D . because he took me out in rough water with my boat, I think it was with the 590hp motor and said he will run it at racing speed. thats because I wanted to race it at that time. it was at least 4 footers, but watching him drive and throttle was cool he had it running a lot harder in the rough than I have, but at the time I just couldn't run it the same speed as him. I just had to learn by myself.[Taking classes is fine in the class room but I would want the teacher to tell me instead of show me]when we got back to the dock he was impressed with the motor, he said he figured it would break:rolleyes: , well the deck did move, found out it got water between the core from the hatches. that was fixed and done better than baja did back then, the new ones 06,07 seem to be state of the art in design and lay up ect, a 35 with standard lay up is running 105 plus with 700s a true 35:D its not dialed in yet so thats the same as some 38footers with built in swimplatforms.