Cobra Lovers - Page 2

hard1 · 18 October 2005, 19:51

Quote:

Originally Posted by codprawn

No transom is definitely the best bet - the Ocean Dynamics boats can shift 2 tons of water in seconds - no scuppers could ever match that!!!

There is one interesting school of thought that has been debated on here before. That is that a waterlogged boat become instantly a lot more stable - a RIB full of water still won't sink but because it's sitting so low it will never flip either - bit like a submerged railway sleeper!!!

Good point. I'm quite sure Dave Picton thought of that when he put his "scuppers" in the Nautique.

codprawn · 18 October 2005, 20:02

Well Alan Priddy would surely know what he is on about - he does have a little "experience"!!!

"If you are in a good quality rib and it h as been designed and built correctly it actualy becomes more sea worthy when it is filled with water! the boat then develops an inforced keel weight and will become part of the sea bobbing up and down until you are ready to make way again. Apart from Spirt, I have always filled my boats with water to see how they float, Do any other Rib builders do this? You do nothave to try this as I have proved that if Spirit doesnt sing neither will Magallen Alpha. ( along with all of the Ribtec range)"

Alan · 18 October 2005, 20:22

Quote:

Originally Posted by codprawn

Well Alan Priddy would surely know what he is on about - he does have a little "experience"!!!

I've tried to fight this but I can't..............

Unlike some!

Alan's right of course although more for an open boat than a cabin rib which he did manage sink in the end

However for a leisure RIB a consequence of having the thing completely full of water is probably your electrics shorting out (unless your battery is mounted high up), possibly making everything live, and possibly knocking out your engine through flooding. That then turns a bad situation worse with the potential for a combination of incidents to spiral into a situation that leads to needing to be rescued.

Open transoms are the thing if you are workingin extreme conditions like the ocean dynamics boats do, but not really the thing for the average ribster. Apart from the bother of getting your feet wet everytime you slow down and get overtaken by your wash, you'll be forever losing things over the transom such as keys, handhelds, phones upto and including passengers!

codprawn · 18 October 2005, 20:43

The Ocean Dyanmics aren't that bad - they have quite a high freeboard so you don't get swamped very often.

I remember seeing a great photo of a Thousand Island thrill ride from a few years ago - the boat was filled with white water and the passengers up to their waists in water - seemed to be loving it though!!!

Good point about the electrics though - better have a sealed battery!!!

hard1 · 18 October 2005, 21:08

Quote:

Originally Posted by Alan

However for a leisure RIB a consequence of having the thing completely full of water is probably your electrics shorting out (unless your battery is mounted high up), possibly making everything live, and possibly knocking out your engine through flooding. That then turns a bad situation worse with the potential for a combination of incidents to spiral into a situation that leads to needing to be rescued.

And that's the limiting factor no doubt!

Mollers · 19 October 2005, 19:01

There is one interesting school of thought that has been debated on here before. That is that a waterlogged boat become instantly a lot more stable - a RIB full of water still won't sink but because it's sitting so low it will never flip either - bit like a submerged railway sleeper!!! [/QUOTE]
No Way is a water logged boat stable. Once it sloshes to one side it'll effectively throw the boat over. It's known as the " Free Surface Effect". Crabbers carry Vivier tanks which are large tanks of seawater in which the crabs are kept alive. The tanks must be kept full and have sealed lids inorder to maintain boat stability.

codprawn · 19 October 2005, 20:17

What you are talking about is a different thing - the same problem that effects people who drive road tankers - liquid sloshing about so high up is deadly.

It is mainly down to the C of G - a submerged rib has most of the weight below the water.

A classic example is a coastal type oil tanker - the bow and stern are raised up but the decks are awash - in fact an oil tanker is one of the hardest boats to sink as the oil is lighter than water.

hard1 · 20 October 2005, 12:46

So much knowledge - in the Photo Gallery Section!!!

MonoMicky · 30 May 2006, 22:37

My new 6.0M Cobra (Mercury 150HP Optimax) at the services on the M6 after picking up from Dave Picton. Some Action shots on the water to follow.
2nd Pic .... The RIB I really Wanted, was intercepted by it whilst trying to sail through a maritime festival on a sailing trip in Turkey but couldnt pursuade them to sell it !!!

codprawn · 30 May 2006, 23:03

The Cobra is a pretty looking boat - ho[pe you have some great fun with it - keep us updated and post some more pics!!!

Roy Smith · 31 May 2006, 23:31

We had a 7.5 Cobra for 2 years and had some great fun on it
but its a costal boat with a hard ride,
Please tell me why do they put the battery in the stern on the floor
next to the tube, my concern was if the tube deflated for what ever reason the batterys open to the sea
and in a big stuffing the water justs flows around the battery
also the bilge on that silly metal brakett.
and last but not least the fact that there is no dry storage
I could go on and on, I just think its a shame that there is no forward develoment. they are a good looking boat and if Picton would just spend that extra bit in the R & D department, i for one would have bourght a second bigger one.
Sorry.
Roy

MonoMicky · 15 August 2006, 20:59

Finally got round to getting some photos on the water, a bit blurred, but hey ... Its a FAST Boat!!

codprawn · 15 August 2006, 22:34

Looks great - must be pretty quick with that engine on it.

Nauti Buoy · 15 August 2006, 22:55

Looks smart, plus same boat name as me

MonoMicky · 16 August 2006, 00:02

CodPrawn .... It goes great with the 150 Optimax, Dave Picton assured me that a 135HP was more than adequate on the 6.0M Cobra but I insisted on a 150HP, ultimately he said If I wanted to waste my money, the 6.0M Cobra would take a 200HP .... YIKES !! It takes off like a rocket and is ideal for deep water start on a mono .... will pull 2 mono skiers up but a little dissapointed in the top end of about 46-48mph, was expecting about 55mph. I currently have the prop that was supplied with it ... a laser II 19 Pitch .... was wondering about trying a 21" Pitch .... Any Advice????

Had some excellent fun on the boat this season, a cracking all rounder with good seating, good storage, well built, nice finish and handles well in the rough ... Was seriously considering a vipermax after being out previously with Humper (7.3M vipermax with 250 E-Tech) and Ribster Rache (upgraded from 5.8M 150 Optimax to Vipermax 7.5M 250 E-Tech) on my little Zodiac Medline I ..... Wanted to Buy Rodgers 5.8 Osprey but thought he had sold it so bought the Cobra and am not dissapointed .... fell for the speedboat luxuries combined with the excellent qualities of a RIB ... my next one will definitely be a Cobra 7.5M with a 250HP ..... but may be a while of yet as am very happy with the 6.0M and I havent won the lottery yet!!! Only one bit of constructive critisism on the cobra and that is the drainage ... not too much of a problem on the water as all the deck drains into the sump at the rear, in the centre, but when cleaning and washing down on dry land (Take note Dave P.) could do with a drain from the deck into the Hull at the front and also on both sides at the rear rather than just in the centre.

Nauti Buoy ...... Good choice in Boat name ... I see you have a 5.85 with a 140HP .... what speed do you get from that? .... Any advice on Props??

MeMe · 16 August 2006, 00:36

......something different - you deserter, turncoat, snake in the grass.........

Where do I get one ?

She looks great, you must be chuffed ? Hope to see ya on the water - in MeMe wake of course

codprawn · 16 August 2006, 04:20

Yes a 21" prop should give you the higher speed - with a bit worse acceleration.

Tony · 09 October 2006, 09:20

Quote:

Originally Posted by MonoMicky

CodPrawn .... It goes great with the 150 Optimax, Dave Picton assured me that a 135HP was more than adequate on the 6.0M Cobra but I insisted on a 150HP, ultimately he said If I wanted to waste my money, the 6.0M Cobra would take a 200HP .... YIKES !! It takes off like a rocket and is ideal for deep water start on a mono .... will pull 2 mono skiers up but a little dissapointed in the top end of about 46-48mph, was expecting about 55mph. I currently have the prop that was supplied with it ... a laser II 19 Pitch .... was wondering about trying a 21" Pitch .... Any Advice????

Had some excellent fun on the boat this season, a cracking all rounder with good seating, good storage, well built, nice finish and handles well in the rough ... Was seriously considering a vipermax after being out previously with Humper (7.3M vipermax with 250 E-Tech) and Ribster Rache (upgraded from 5.8M 150 Optimax to Vipermax 7.5M 250 E-Tech) on my little Zodiac Medline I ..... Wanted to Buy Rodgers 5.8 Osprey but thought he had sold it so bought the Cobra and am not dissapointed .... fell for the speedboat luxuries combined with the excellent qualities of a RIB ... my next one will definitely be a Cobra 7.5M with a 250HP ..... but may be a while of yet as am very happy with the 6.0M and I havent won the lottery yet!!! Only one bit of constructive critisism on the cobra and that is the drainage ... not too much of a problem on the water as all the deck drains into the sump at the rear, in the centre, but when cleaning and washing down on dry land (Take note Dave P.) could do with a drain from the deck into the Hull at the front and also on both sides at the rear rather than just in the centre.

Nauti Buoy ...... Good choice in Boat name ... I see you have a 5.85 with a 140HP .... what speed do you get from that? .... Any advice on Props??

Hi Mono
I'm considering a 8.5 Cobra, have you been in one, or do you hve any comments about them?

MonoMicky · 09 October 2006, 21:56

Tony .... Never been in an 8.5 Cobra, or an 8.5 of any other RIB come to that

Based on the quality and ride of the 6.0M, I am sure you would not be disapointed. Sorry I cant be of more help .... there must be someone on here that has been in a Cobra 8.5

Ezgoing · 15 October 2006, 22:40

Mono

Forget the Rib.

Just get me the gun!!!!!!