Anchor for 7 metre RIB

Paul · 15 June 2006, 08:48

I am about to take delivery of a 7 metre Humber Ocean Pro. I would be interested to know what people regard as a suitable anchor for such a boat as well as the length of warp/chain that I should be using.

Hugh Jardon · 15 June 2006, 08:54

if on sand then a 5kg bruce will do the job, and chain the length of the boat is a good rule of thumb

i had one of those 4 legged umbrella style anchors initially in cornwall and on a slightly rougher day it would not hold but alices 5kg bruce held hers and mine, and did not budge an inch, so two boats on one anchor!!

bruces do not fold or anything so you wont pinch your fingers etc

the folding anchor thing i had is ok for rocks apparently

the 5kg bruce is around 25 quid and money well spent.

Paul · 15 June 2006, 08:58

Thanks for the quick reply. How much warp do you attach to the chain?

Alice · 15 June 2006, 09:13

Quote:

Originally Posted by Paul

Thanks for the quick reply. How much warp do you attach to the chain?

About a boats length of chain or a tad less, as much warp as you can sensibly carry without jamming up your anchor locker. I always carry extra stored elsewhere on the boat. If the motor goes Phut with an onshore sea/wind, that anchor might be the difference between you and the rocks.

Nick Hearne · 15 June 2006, 09:15

How deep is the water you want to anchor in?
You want about 5 times your depth in rope

Jono · 15 June 2006, 09:19

I use a Danforth (type.. might not be genuine..) on my 7.0 'Umber.. I bought the biggest one that I could fit in the anchor locker and it sits ontop of the warp and chain nicely I think it was about 10KG.. it (and the chain) also helps trim the boat very nicely if I stick the auxilliary on the arse end...

PS.. you can never have too much warp, chain or anchor... if you're a devout coward..

Hugh Jardon · 15 June 2006, 09:21

i purchased the cheap blue bailer twine stuff that works a treat but roy and alice took the piss but you can get 100's of m for a few quid. Initially purchased it as a stop gap as was cheap as chips until i could identify the best stuff to get. was around 6 quid for 60 m i think or even better.

Alice · 15 June 2006, 09:26

Quote:

Originally Posted by Hugh Jardon

i purchased the cheap blue bailer twine stuff that works a treat but roy and alice took the piss but you can get 100's of m for a few quid. Initially purchased it as a stop gap as was cheap as chips until i could identify the best stuff to get. was around 6 quid for 60 m i think or even better.

Polyprop, lovely stuff. It catches fire if you load it up enough.

Hugh Jardon · 15 June 2006, 09:27

Quote:

Originally Posted by Alice

Polyprop, lovely stuff. It catches fire if you load it up enough.

under water?

never did ask, what is the best warp to get that is cheap or reasonably priced?

Seaharrier · 15 June 2006, 10:21

We bought a mooring package from plastimo:

46566 - Mooring package for boats : 6 - 8 m
Set : Kobra anchor 6 kg, chain, rope and shackles.

Kobra anchor 6 kg
Chain 10 m, Ø 6 mm / Stranded polyamide 30 m, Ø 8 mm
Galvanised bow shackle Ø 8 mm
Total weight 16.4 kg.

Price is 175€

Tim M · 15 June 2006, 10:30

I'm using an 8kg grapnel. I'm yet to test it but I think it should be fine for my boat (quite light). Bought it becasue it folds up so small. Had one on my 4.1m (2kg) and it held really well (had ten meters of chain attached though)

Alice · 15 June 2006, 10:59

Quote:

Originally Posted by Tim M

I'm using an 8kg grapnel. I'm yet to test it but I think it should be fine for my boat (quite light). Bought it becasue it folds up so small. Had one on my 4.1m (2kg) and it held really well (had ten meters of chain attached though)

Hey Hugh, have a word re.grapnels and sandy bottoms.

Hugh Jardon · 15 June 2006, 11:10

Quote:

Originally Posted by Alice

Hey Hugh, have a word re.grapnels and sandy bottoms.

grapnels are crap crap crap on sandy bottom, you could use a 2 or 3kg bruce instead of a 8kg grapnell and i am sure it would hold loads better. Bob and i used grapnells and we just could not hold, i got a bruce same as alices as that proved itself when we both anchored to it, bob is getting a new anchor as well i beleive

bruces are nice cos they dont have those moving bits that pinch your fingers

just our experience over the last two weeks

BogMonster · 15 June 2006, 12:31

I haven't used it yet but I looked at the anchor on mine and thought it was a bit small, its a Danforth type not sure of the weight but prob about 8-10kg. Then I saw a similar sized anchor on a 12 tonne Halmatic launch and figured it should be OK for a 1/2 ton rib

On mine it is just the right shape to perch securely in the compartment in the bow sitting on top of the heap of chain and rope (think there is about 50m of rope).

Can I hijack the thread slightly; how often do folks think you should change the rope on the anchor? Deterioration of the chain is fairly obvious but rope....? It's probably the original one so about 6-7 years old.

codprawn · 15 June 2006, 14:14

Quote:

Originally Posted by BogMonster

I haven't used it yet but I looked at the anchor on mine and thought it was a bit small, its a Danforth type not sure of the weight but prob about 8-10kg. Then I saw a similar sized anchor on a 12 tonne Halmatic launch and figured it should be OK for a 1/2 ton rib

On mine it is just the right shape to perch securely in the compartment in the bow sitting on top of the heap of chain and rope (think there is about 50m of rope).

Can I hijack the thread slightly; how often do folks think you should change the rope on the anchor? Deterioration of the chain is fairly obvious but rope....? It's probably the original one so about 6-7 years old.

Sunlight is prob the worst killer of rope. If the rope looks fine with no nasty abrasions etc and hasn't been kept in the sun you should be fine.

Know what you mean about OTT mooring tackle. I have 2x50m lengths of 16mm rope - that's over 300' in real money - plus about 20' of stupidly heavy chain and a 14lb danforth. Plenty of room for it all.

For day to day stuff I have a big folding grapnel - yet to try it though. I know they are crap in sand but they are better than most in foul ground.

randski · 15 June 2006, 15:56

Quote:

Originally Posted by Hugh Jardon

Bob and i used grapnells and we just could not hold, i got a bruce same as alices as that proved itself when we both anchored to it, bob is getting a new anchor as well i believe

I got a 5kg bruce last week and used it at the weekend on the North coast. it held me and Ian Parkes well. (That's not just Ian - his boat as well) So much better than grapnells.

and it fitted in the anchor hold...although there's no room for my spare fuel cans anymore - Ooops, I don't seem to have any spare fuel cans anymore!

mark-f · 15 June 2006, 15:59

My Personal choice after trying most of the anchors types over the years is a 5kg bruce which is rated as a storm anchor for powerboat upto 25" but a CQR or danforth are probably almost as good ( my view that is), i would use 10m chain, as the the rule of thumb of 1 boat length of chain then rope, is a minimum in my view!!

then make sure that your total chain & rope is at least 6 times depth, preferably 7 times if possible, really depends on how much you want to make sure you boat doesnt move too far from where you left it.

As to the folding grapnel type anchor, they make a good mud weight if unopened and they do pack up neatly on a boat......yep thats the only positives i can think of for them

mark

Alice · 15 June 2006, 16:13

[QUOTE=randski] I don't seem to have any spare fuel cans anymore!

/QUOTE]

Last seen flyin' around the Penryn area!!

Sorry Bob, are you on the water on Sat or Sun? If not I'll drop them up to your place.

Jelly · 15 June 2006, 16:17

I have a 7.5 KG Bruce with about 30m of chain and 50 odd m of line.
Basically the biggest anchor I could get in the locker and you never know what might happen.
I also have a pickup bouy on the end of it incase I have to let it go because of a snag etc so we can retrieve it later.
We also have a 5kg CQR thats going to be rigged as a spare / lunch pick.
Jelly

Richard B · 15 June 2006, 16:23

A quick point here about the theoretical "scope" (ie how much anchor line to put out)....

If you are anchoring amongst other boats, put out a similar scope to everyone else, regardless of the theoretical calculation. If you put out much more, when the tide turns you'll swing around in a greater arc to everyone else and very likely either hit the other boats or tangle your lines.