What if you hit this at near WOT speed??

[Mark P]

I was walking with the Admiral on Hilton Head Island yesterday (hoping Governor lifts stay tomorrow so we can head out for a bit), and saw this laying on the beach. From the looks of it, this palm tree has been out there for some time. Since I ply these waters frequently, I started thinking, what if last month I would have hit this thing at near WOT speed? For me that would be near 30-35 MPH. Given my boat, the damage would have been probably catastrophic and maybe lost the boat. What about your vessel?

 

[O C Diver]

It would depend on how much of your bow comes out of the water on plane. If you have an I/O, the lower unit is probably history. If the bow is down in the water, probably not much left of the front of your boat. Were you planning on be seated and restrained when you hit it?

Ted

 

[PM]

bump, Maybe knock the Admiral out of bed, maybe not.

Hard to do much damage at 7 kn.

pete

 

[Mark P]

OC. I rarely go that fast but when I do, I am usually 1/2 sitting on my seat. If I slowed from 35 mph to 20 mph because the stern drive hooked that palm tree, I would likely really get hurt - probably flung into windshield which is angled toward me. Of course on the bright side, my insurance would cover plastic surgery, some tooth implants etc.

 

[O C Diver]

Coming back in from an offshore charter in 3' seas, I came down on a telephone pole in the trough at 15 knots. The heavy fiberglass keel was undamaged and the skeg protected the prop and rudder as the boat slid over it. From the impact BANG, I was sure the hull broke and we were going to sink. If I had hit it when it was at the crest of the wave and the boat was cutting through the wave, probably a different outcome.

Ted

 

[PM]

I one time "rolled" over a waterlogged log laying on the bottom in shallow water. Gravel/sand bottom on a river. I probably had six inches of water under the boat, the log must have been about 8 or 10 inches. I felt it from the bow to the stern as we rolled over it.

Scared the pants off me but did no damage, Just lost a little paint on the bottom of the keel.

pete

 

[rslifkin]

I think Pete and Ted have it covered. It's all down to how you hit the thing.

On my boat, if I went up and over it perpendicular to the log (at any speed), I'd have prop damage once it came off the back end of the keel right into the props. The rudders don't reach to the bottom of the props, so they might survive. If I whacked the log lengthwise, I'd say at low speed it probably wouldn't be too eventful, would likely get pushed off to the side. On plane, I'm not sure. Might get pushed away, might hit the hull (maybe hard enough to do damage), might go under and take out a prop.

I did have an encounter with an unidentified submerged object (never saw it before or after the hit) over the summer, but I was only doing 7 kts at the time. One heck of a bang (felt like someone smacked the bottom of the hull with a sledgehammer), enough that I immediately handed off the helm and went below to confirm no signs of a problem, then throttled up a bit to check for vibrations. No resulting issues, and looking at the hull this winter, I can't even tell for sure where it hit (I've got some bottom paint chips, but nothing obviously impact related). Depending on how you hit something, boats can be surprisingly sturdy, although running gear is typically the most vulnerable to damage (short of a hull-puncturing impact).

 

[psneeld]

I have pulled many a boat off the marsh, from hitting one another, objects in the water, sandbars, jettiies, etc.

There was the full spectrum of damage depending on the circumstances....from little to catostrophic. Often very little damage with outboard or stern drives as they ride up and over.

The jetty hits were usually the worst....usually because the boat stopped, but the waves kept pounding them on the rocks.

 

[rslifkin]

The jetty hits were usually the worst....usually because the boat stopped, but the waves kept pounding them on the rocks.

Makes sense to me. Instead of just worrying about how well the hull can handle the impact forces, you now have the issue of point stuff trying to chafe through the hull.

 

[boathealer]

As above, WOT is 8kn. Hull is 2in of solid glass with beefy skegs/shoes. No problem.

 

[CaptTom]

Funny nobody has yet mentioned keeping a good lookout.

These sorts of things are exactly why I keep my eye on the water ahead ALL the time. Just habit, from a lifetime of dodging lobster buoys.

I have seen, and avoided, thousands of things like that in my life. Others I haven't seen and passed closed by. I've never hit anything that big, but it certainly could happen. Another reason I'm OK going trawler speeds.

And it's not just logs or lobster/crab trap buoys. I've seen all kinds of half-sunk debris, from docks to water heaters to a refrigerator once. I've never seen a shipping container, but some folks say they're out there, barely visible floating just at the surface.

 

[4fun1]

Or you can have something like this. When I hit something submerged at about 12 knots in the Barneget Bay

 

[slowgoesit]

In Puget Sound, just coming up on the Narrows bridge (only one at the time), at night, we hit something 'Bump, rumble, rumble, rumble, rumble, BANG!'
34' Monk, doing about 6 kts thru the water, 12 kts or so over the ground (outgoing tide). The Bump was the initial contact, the rumble, rumble rumble was the log (I assume) which we hit perpendicular rolling under the hull, on the chine and the keel, the BANG was the prop hitting the log. Someone else was at the helm, didn't know what to do, I yelled "Cut the throttle!", ran forward, got there just as the Bang happened . . . bad vibration when we started moving again. Limped into Gig Harbor, had to replace the prop shaft and the prop. Couldn't possibly have seen it in advance, just one of those things.

 

[Bacchus]

Been There Done That

I have had that experience - not with our boat but a friends Tiara w/ Twin Diesels and IPS drives. The log was about the dia of a telephone pole and approx 20 ft long. Visibility was poor with ripples on the surface of an otherwise pretty flat surface. Stalled out the engine and certainly threw us off balance.

The Bad News - dead in the water got towed in vs trying to run on one engine as we knew nothing about extent of damage until after.
Took out dual props on one drive

The Good News - damage was limited to props and only on one drive.
Indicated the shaft and it was as straight as new... actually it was new and a delivery run!
No damage to hull - didn't even scrape the bottom paint off!

I was surprised a how rugged the drive was and that the only damage was to the props. As an aside a prop shop refurbed theses and came back good as new. That shop is now my Go To for any prop work.

 

[Duvie]

Hit an awash pressure treated 2x4 or 4x4 with my Boston Whaler 13 at about 25 knots. The 10 or 12 foot long board was perpendicular to the boat. Luckily the motor was not locked down. I cut throttle as soon as I saw it, the motor raised up on its own and I don't recall hearing anything but maybe a slight bump.

 

[Russell Clifton]

Those kind things are pretty common place in the Pacific Northwest. Especially bad when the rivers run high and dump lot's of junk into the sound, or when we have very high tides (king tides) in conjunction with a wind storm that will suck really big logs off the beach. That's why I never ever run after dark. Also need to keep a constant lookout ahead of you. I try to avoid anything up ahead as you never know what lies under it that you can't see. I don't worry so much about my running gear but there are two stabilizer fins hanging out in the open. Even at 7 knots I still on occasion will hit something.

 

[firehoser75]

Like Russell,
We too run at 7 knots and keep a constant watch for debris as there seems to be a never ending supply of floating and worse yet, partially floating "junk" (mainly logs). The worst I have seen (and was lucky that I did) was a log (deadhead) floating (bobbing up and down) vertically, most of the time just below the surface, occasionally breaking above the water by a couple of inches. The diameter of this hazard was about 3 - 4 feet. It was just luck (timing) that I even saw it!! It was not just a "stump", but was very long as well. If someone hit that thing at any speed, it would not move easily.

 

[Ka_sea_ta]

There are aluminum "camp boats" that transport crew and supplies to remote logging camps in BC.... There boats are primary power with diesel stern drives and cruise probably 25 to 30 knots. They routinely hit logs at that speed. In order to protect the stern drive (legs) and props. they all have a log jumper welded on the bottom of the boats. This is basically an aluminum keel that is positioned in front of each drive and depth is approximately the same as the stern drive. When they hit a log at speed the stern is forced up, the log down and the drive is protected... some builders offer this as an option on their pleasure boats.

 

[syjos]

When we had the 34 Mainship in the 90's we ran over a log doing 9 knots. It was about 12" in diameter, 10' long and completely awash. We did not see it and hit it perpendicular about in the middle.

When we ran over it, the bow rose and we could feel and hear the log rolling under the hull. Not a happy sound or feeling. I shoved the single into neutral. We looked behind us and when the log emerged from underneath the transom, it flew up into the air about 10 feet. We were lucky that we were still moving forward at a good clip because any slower and the log could have taken out the swim platform and the dinghy on the Weaver bracket as it flew up.

I did an immediate bilge check for issues and found none. Placed the engine in forward and no vibration. Moved the rudder, no restriction. We got underway, quite shaken up.

We made it a short day and anchored at the first opportunity. I dove under the boat and other than scuff marks on the bottom paint, I did not see anything amiss.

We were fortunate that the Mainship was a single with a rudder shoe protecting the prop. We were fortunate that we hit the log at 90° where the log was bridged between the keel and chine avoiding the prop. Had we hit the log at it's end straight on, the ending may have been different.

That was the largest log we ever hit. We have hit smaller ones with no damage.

That happened over 30 years ago when we were still new at big boat boating. It scared the absolute crap out of us and that incident has made us a lot more careful at looking ahead for disturbances in the water. We have been able to spot submerged logs and deadheads by the disturbance in the water when the seas are not rough.

 

[CaptTom]

I have had that experience - not with our boat but a friends Tiara w/ Twin Diesels and IPS drives.

Perfect timing. Just got a call about a delivery gig for a Tiara with IPS drives. I always worry about those things. Glad to hear they're more robust than they look. Still hope I won't find out first-hand.

 

[koliver]

I used to carry deadhead marking flags, and in my early years of boating, used them frequently. They are best on those vertical deadheads that are fully submerged close to 50% of the time. If you hit one, you may never have had the opportunity to see it. Some of the ones I flagged sank with the added weight of the 3'x 1/4" staff pounded into the endgrain.

More recently, those hazards are still around, though way less frequent. This is due to a change in stumpage rules many years ago, so that the stumpage is now paid on the logs that enter the water, ie: At the logsort, rather than the old rule of payment only for the logs that arrived at the mill. Now most are carried on self-dumping barges and booms are all bundled with cables, so the serious hazards are the logs swept down the rivers and old beached logs liberated by high tides and storms.

 

[Bacchus]

Perfect timing. Just got a call about a delivery gig for a Tiara with IPS drives. I always worry about those things. Glad to hear they're more robust than they look. Still hope I won't find out first-hand.

Tom

The only parts that are not robust are the props and they are VERY unprotected facing fwd. In fact, they tend to suck everything into them.
I'm convinced with this incident and others my friends has had since that I do not want any Pod drives... I'll take a single and thrusters any day.

Might be worth inquiring if new owner has or has thought about a set of spare props - They are the same port & stbd so one set could be somewhat universal.
You might at least do some pre scouting to know who in the area had a set in case they are needed.
As I recall there is one special tool req'd to remove / replace the props and not every yard / marina has experience or the tool.
If you need / want more info on tool & procedure I can ask my friend and let you know.

 

[O C Diver]

I'm part of the 7 knot crowd and only travel at night in specific situations. When running my charter boat at night in the ocean, we slowed to about 10 knots which kept the bow up on a downeaster plane (not fully on plane with modest wake). Even during the day, you're just not going to see everything. Went over a giant turtle just as he was surfacing. No time to react. I was on plane and he dropped. Never touched him. The keel and prop missed him and the rest of the boat was within inches of the surface. Sometimes it better to be lucky than good.

Ted

 

[rslifkin]

Sometimes it better to be lucky than good.

Agreed. And I'm also in the slow down at night club. It's pretty rare for me to get above 7 kts if I'm running in the dark. And if I do go faster, it won't be near land or anywhere with any meaningful boat traffic and only if I'm pretty confident that I'm in water where I'm unlikely to encounter any debris.

 

[Northern Spy]

I used to carry deadhead marking flags, and in my early years of boating, used them frequently. They are best on those vertical deadheads that are fully submerged close to 50% of the time. If you hit one, you may never have had the opportunity to see it. Some of the ones I flagged sank with the added weight of the 3'x 1/4" staff pounded into the endgrain.

More recently, those hazards are still around, though way less frequent. This is due to a change in stumpage rules many years ago, so that the stumpage is now paid on the logs that enter the water, ie: At the logsort, rather than the old rule of payment only for the logs that arrived at the mill. Now most are carried on self-dumping barges and booms are all bundled with cables, so the serious hazards are the logs swept down the rivers and old beached logs liberated by high tides and storms.

I still have some markers kicking around in the lazarette. They are 2"x2"x2' painted orange cedar with a nail in one end. Never really liked getting close enough to the deadhead to mark... just enough positive buoyancy to make those things real scary when they come back up.

Still see some big stuff in the tidelines after a king tide. Everything that gets deposited on the South shore of Harwood all winter, comes back into the water and seems to hang around for days.

 

[boatpoker]

Perfect timing. Just got a call about a delivery gig for a Tiara with IPS drives. I always worry about those things. Glad to hear they're more robust than they look. Still hope I won't find out first-hand.

The entire drive is designed to sheer off. I've done a few claims investigations on them.

 

[GFC]

Many years ago we had our 33' express cruiser in the San Juans and were headed back to Anacortes at the end of our trip. Out in the middle of nowhere we ran into a field of railroad ties that apparently had been dumped off a barge.

Hundreds of them, mostly floating just at the surface of the water. We eased our way through them and could hear them as they bumped along the bottom of the hull. Every time I'd come up to one I'd shift into neutral and just coast. It took about 20 minutes to wander our way through them then it was clear sailing to Anacortes.

 

[Spinner]

Nope, no night running for me!! Too much wood debris in the water.

The worst thing I ever hit was some kind of mostly-submerged large bush! It wasn’t tree roots, as I could see it when it bobbed up behind me. Made some noise as it passed under the hull, but no damage was done. The most wearying thing about single-handing in this area is the need to be constantly on the watch for debris. It’s not a problem in flat calm water, but in large chop or waves, it’s really difficult to spot the stuff....

 

[Lou_tribal]

Not uncommon up here to encounter a log in the river. With ice melting in spring, all sort of debris are moved into the flow. Biggest I have seen are a dock almost 20' long and a tree with its roots but these are easily seen. What I really hate are the logs vertical in the water that are moving up and down and barely visible. This is why we always keep a watch ahead. While these are mostly in spring some can still be encountered all season.
Fortunately at 7 knots I have plenty of time to divert myself but still sometime we get surprised by one showing up 30 feet ahead.

L

 

[DDW]

The entire drive is designed to sheer off. I've done a few claims investigations on them.

Friends of mine tested this. A modest grounding (they described it as low speed and without much drama) sheared both IPS drives. While they are designed to shear and save the boat, they are not designed to save themselves as they flood with seawater and must be replaced. Last I heard the insurance settlement was climbing north of $200K and still going.