Ribs that slam.

[jambo]

Originally Posted by Bigmuz7

But only for certain hulls ive found of similar size, some will not do this at all, and you also need the horsepower too

That's what I meant when I said if you AND YOUR RIB can handle it!!

Sent from my iPhone using Rib.net

[jordan-11]

Originally Posted by HUMBER P4VWL

The only true way would be compare two boats from one brand such as a 5.5m Humber. A destroyer vs the Assault. I've not been in both, but have seen them in the sea. It's plainly obvious which you'd cross the overalls in!!!

Which one? I only have experience of the destroyer?

[Mextli]

I once could compare my SR4 with a flat-keeled 4m RIB on one of the rivers here, the wash from the big ships tends to be around 1-1 1/2 metres tall.

Both boats would fly over the waves if driven into them at speed (the Searider more than the other one but that was due to reasons of speed, whilst the other one managed 24mph the Searider went at 43mph) but the impact of the Searider was much more bearable, even at higher speeds. The flat-V, even when driven gently through these short steep waves slammed so much that me back hurt.

If you overdo it with speed or the boat is very bow-light, even my Searider slams(If I'm out into bigger waves, i always put a sand bag in the bow/alter engine trim when I'm alone. A second person sitting on the console(its quite far forewards) solves these problems), but if you drive gently, usually the boat gives a very soft ride.

[HUMBER P4VWL]

Originally Posted by jordan-11

Which one? I only have experience of the destroyer?

Yours has a far deeper V. Nice boat.

[biffer]

I've read all these threads and haven't seen any mention of chine and spray rails, these have more effect on slamming than shallow/medium/deep v hulls, the more flatted areas you have parallel to the water the more slamming you have, you could have a deep v boat with large rails that will slam, have a look under a hull and add up all the area that is facing straight down, three rails either side can amount to quite a larger area. I could go on about reverse chines and boat design but I've run out of tea

[HUMBER P4VWL]

Originally Posted by biffer

I've read all these threads and haven't seen any mention of chine and spray rails, these have more effect on slamming than shallow/medium/deep v hulls, the more flatted areas you have parallel to the water the more slamming you have, you could have a deep v boat with large rails that will slam, have a look under a hull and add up all the area that is facing straight down, three rails either side can amount to quite a larger area. I could go on about reverse chines and boat design but I've run out of tea

Very good point biffer. Our Ocean pro sits higher and gets up quicker than the smooth hulled destroyer as the large spray rail gives lift and helps push water away. Conversely I guess we slam more, but less likely to stuf too.

[boristhebold]

I think most ribs will slam but depends much on how fast your going or how high you get airborne or wave conditions + length, weight and V type is all a factor. Plus how your outboard is trimmed can have an effect depending upon water conditions to how comfortable a ride will be.

From my own experience I have a 7.5M cobra and only slams if im pushing it over routh seas with biggish waves and I get airborne, ive watched the might parker from sea safari go through some overfalls off Old Harry in Poole, it tends to dig in and slice through the overfalls where as my rib will slice through to some extend but definately seems to try and go over the overfalls at times if im gunning it. The difference would be the extra weight of the mighty parker and the extra length in my humble opinion. I could go faster probably on a calm sea but know I could not keep up with the parker in rather rougth conditions well not without a great deal of pain on my back and knees I expect.

So for most V ribs I would expect heavier and longer ribs to be less slammy than lighter shorter ribs.

If we could all aford it we would all have 10M heavier ribs, so much in life is a compromise. Now where is my lottery ticket.

[kerny]

Originally Posted by biffer

I've read all these threads and haven't seen any mention of chine and spray rails, these have more effect on slamming than shallow/medium/deep v hulls, the more flatted areas you have parallel to the water the more slamming you have, you could have a deep v boat with large rails that will slam, have a look under a hull and add up all the area that is facing straight down, three rails either side can amount to quite a larger area. I could go on about reverse chines and boat design but I've run out of tea

biffer, I was going to mention chine's, the only reason being is that a RIBnet member off here came to my house to pick up some fuel tanks and mentioned that he was going to change his Humber 5 mtr + which had a medium v hull because it slammed , and that he was looking at getting an Osprey. My rib was covered up on my drive but I did say to him that my rib does seem to be decent in the rough so I lifted up the cover on my rib and he looked underneath, and the first thing he said was it was the extra chine's on my hull. Never thought much about it until you mentioning it.


H.P. all the times I have been out on my boat never once has it stuffed ( I'm not saying that it never won't) and going round Anglesey on our rally it never once stuffed although Matt H had to grab me on a couple of occasions to stop me falling over but that was due to being hit side on by some big waves.

Coming out of Holyhead Matt took the helm right up to Carmel head and he said he loved it and wanted to do his wave jumping and stuff he is mad I'm sure that when he see's this thread he will tell you how well it handled.

Now at the beginning of this thread my question was mainly on small boats because the ones I have been on did not seem to be any different than mine which has a medium v.

Looks like biffer has explained this in one paragraph. Thank you biffer

[Maximus]

Originally Posted by jambo

There is a lot to be said about powering into the weather if your rib and you can handle it, it does make for a smoother ride. It does take a bit of getting used to though as it is kinda against the smart thinking

There is no doubt that Driveing Style has alot to do with a Softer ride with less Slamming...I know when it happens to me I fell ''I got that one wrong!''
The worst boat I ever had for it was a Flat Bottomed Dory...Bloody Horendous!!..Compared to them even the worst Type RIB is a whole world Better!..
I have also noticed that if a V hull is continued to the Stern..even if only a shallow one,it makes for a much softer/easier re-entry in the rough...Especialy in a following Sea.
The Planeing Pad type Hulls although often slicker on the Flat...do tend to Slam more in the Rough.
All Hulls have thier Pro's and Con's,and are by thier nature a Comprimise.. IMO its all about chooseing the Best Hull-Boat to suit the type of Boating you do,and the Conditions you most encounter....One thing for SURE if its rough Water on a Budget....Its a RIB!

[HUMBER P4VWL]

No slight on your boat meant Steve, I just meant that if you power up to broach waves, at some point when the pattern lengthens you will nose dive in to the next one and a stuff will occur if going fast enough in to a big enough wave, in any boat!

[two stroke mick]

I removed and replaced the console on my rib. The new console is further forward which improved the balance greatly. The boat is now less likley to slam. An unforseen side effect of moving the console and thus the battery and fuel forward is that the boat is now a wetter ride than was the case before.

[Exe treme]

I have only had experience of sub-6m boats but the best riding hulls of these had a curved keel profile rather than a flat one. A simple example would be a surfboard versus a snowboard. The curved hulls tended to rock over the chop whereas the flatter designs slammed more. Not much use on Ribnet I know, but the most comfortable hull I have owned was an 18ft Wellcraft hard boat. It had the curved profile but only a medium entry V. The most comfortable Rib I owned was a 5m Lomac with a similar hull design. Believe it or not, it was a cat B as well!

[biffer]

Originally Posted by two stroke mick

I removed and replaced the console on my rib. The new console is further forward which improved the balance greatly. The boat is now less likley to slam. An unforseen side effect of moving the console and thus the battery and fuel forward is that the boat is now a wetter ride than was the case before.

This again is down to experience and design, I bet the water comes over on the shoulder of the boat, just where the tubes straighten out to go aft

[two stroke mick]

I havent taken much notice of were it comes from but I will. The fecking sea is soo very cold at the moment I get brain freeze when it hits my head (Similar to eating ice cream too fast)

[hadd]

Originally Posted by mick

We noticed it coming down the sound of mull in a head on sea if we went slow we went up and down the waves but when we got a decent pace we could skim across the tops making a smoother ride

Yep!! Speed makes a difference as well , going across to Ireland last year my RC545 kept up with all the bigger boats I think it's all on the sea conditions on the day & distance between the waves & speed that you travel at also the person at the helm

[Bigmuz7]

Originally Posted by biffer

I've read all these threads and haven't seen any mention of chine and spray rails,

Ahem

post #7

Originally Posted by Bigmuz7

I have noticed though that the current 5.4 hull I have is an old Tornado design which has very aggresive spray rails, and Ive been amazed how well this boat handles, in chop , as any water sliding up the hull gets pushed down hard .. and these come right to the bow .. which many other hulls Ive looked at dont .. they are smooth up front.

[biffer]

Originally Posted by Bigmuz7

Ahem

post #7

Sorry mate I stand corrected

[HUMBER P4VWL]

Originally Posted by biffer

Sorry mate I stand corrected

Tsk, go and chastise yourself and ask for forgiveness.

[biffer]

I see the rest of this went in the bilges, I really didn't mind getting pulled up, I must explain though, I missed his post cause I didn't read it, most of the time he's taking the piss or winding someone up so I assumed he was doing the same, I did need to apologise has he did have something constructive to say

[two stroke mick]

This was one of the most interesting posts/ observations/ question that had been put to this forum in some time