I learned a valubale lesson in flotation today...

[fweasel]

Proboat Impulse 31 V3. Now you see it, now you don't

I'm not sure what caused it to hook suddenly and nose in. It's a very soupy mud and silt bottom. I believe the boat augured in and when the mud finally released it, the damaged hull collapsed which sent up an eruption of large air bubbles about 2 minutes later. Had I simply just lost the hatch, that would have surfaced on its own. I'm not too concerned with loosing the boat, but am bummed about the GPS, 2 Revo batteries, and a Dasboata prop. If I'm going to loose that much all at once, I want spectacular aerobatics, debris fields, public property damage liability issues, wildlife endangerment, and a burning oil slick on the surface of the water. All I got was bubbles.

In case anyone wants to go dive for it, it's right here...

2017-09-04 12.00.44.jpg

[boatsrnew2me]

i had read that this boat can do that ,but thats the first i seen it . has it surfaced yet?

[rol243]

r/c electric boats should always have the cowl / lid taped down not just clipped on so when your flip it upside down it just fills with water and ruins the electronics. tape the lid and gain bouyancy plus save your electronics.

[fweasel]

i had read that this boat can do that ,but thats the first i seen it . has it surfaced yet?

Nope, we were there a solid hour after that running two other boats. It's gone.

r/c electric boats should always have the cowl / lid taped down not just clipped on so when your flip it upside down it just fills with water and ruins the electronics. tape the lid and gain bouyancy plus save your electronics.

The hatch was securely taped down.

[rol243]

when the hatch is fully sealed there is a large amount of air inside that acts as good bouyancy but if there is a leak in the seal theres no bouyancy left.

[fweasel]

when the hatch is fully sealed there is a large amount of air inside that acts as good bouyancy but if there is a leak in the seal theres no bouyancy left.

In my original post, I mentioned a large eruption of air bubbles about two minutes later which is when I suspect the boat was released from the mud exposing a catastrophic hull issue, and imploding.

[TRUCKPULL]

A few years ago at one of the big races, we had a boat do that. Everyone thought it was gone after about 5 min.
The next day during a race, the CD yells "Dead Boat in turn 3"
Well with 5 drivers on the stand and 5 boats still racing, we all said "WHAT"
It was the boat that went down the day before, It was over 10 ft. deep in the section of the pond.

When you saw the large eruption of air bubbles, was there a little bit of white smoke with it??
I have seen this happen from batteries under water.

Larry

[MADRCER]

Man that's horrible! I had my Impulse 31 do nearly the exact same but I got it back with just the hatch cover blown apart by the impact. My GPS flew out of the boat also and was never recovered. That's where I got the idea of the little black duffel bag zip tied to the inside of boat. By the way I didn't keep that boat much longer after that either. Man I hate that feeling...

[Doby]

A few years ago at one of the big races, we had a boat do that. Everyone thought it was gone after about 5 min.
The next day during a race, the CD yells "Dead Boat in turn 3"
Well with 5 drivers on the stand and 5 boats still racing, we all said "WHAT"
It was the boat that went down the day before, It was over 10 ft. deep in the section of the pond.

When you saw the large eruption of air bubbles, was there a little bit of white smoke with it??
I have seen this happen from batteries under water.

Larry

That was Jays P Mono...I remember that race....water did get in the hull but he had enough flotation that when the mud let it go..up it went.

[Peter A]

Pool noodles, as much as can be fit, displaces water and provides bouyancy.

[rol243]

yes never go boating without adding floatation. this is lesson number one in the r/c boating industry. i remember some years back where this new guy and a brand new glow powered cat hull all worth about $2000 flipped the hull and within 30 secounds it started to go down . its still submerged in the same spot it went down in approx 20 meters of merky water, a diver couldn,t see it due to the merk.

[Insanity Plea]

I'm not sure the hull would actually implode. I don't know the depth of the water but imploding is caused by the surrounding pressure which increases with depth and causes it be crushed like a soda can. It's quite possible that it became dislodge from the mud with hull damage and all the air escaped before the boat could reach the surface.
A GoPro case can reach 200ft before showing signs of fatigue from the pressure. A cheap plastic water bottle starts imploding around 20ft and will be flat at 75ft.

[fweasel]

Based on the short duration and quantity of air released, I suspect it was all released at once. That's what I meant by implode, not purely a pressure related breach based on depth.

[rol243]

when you look close at the video , the boat suddenly flips and very slowly sinks. it doesn,t spear under the water atall. thats how it looks to me anyway.

[fweasel]

We had a good clear shot of it when it happened, it was there one second and gone the next. There was no sinking.