Harbour Speed Limits for Mbos.SOG or What?!

[Scotty_Tradewind]

Is this ...........Speed Over Ground, or Speed Through the Water?

Portsmouth this weekend 5M spring tide.

As I plod my way in against a fast spring ebb which does its best to spin me away from my course when approaching the mouth of the harbour, a mobo comes passed me in the small boat channel and cuts inside my bows causing me to lurch violently from side to side in his wake.
I'm thrown from side to side, worse than being in a confused sea in a F7.
Why do mobos do it........ my crew, a petrolhead of a car mechanic has his own liveaboard yacht. "I'd go round sinking the lot of them with an electric drill if I thought I would get away with it, just to get rid of them for a week."
This normally peace loving calm romantic is often brought to a rage when he gets buzzed by jetskis, speedboats and stinkpots.
Why can they not go where it doesn't effect others for ****** sake?

 

[snooks]

Why can they not go where it doesn't effect others for ****** sake?

Matie in the Mobo prolly had been where he wasn't effecting others....he was just coming back

 

[Elessar]

Editing out the rather boring and repetative ranty bit it is a good question.

Firstly it is not a speed limit for mobos it is a speed limit.

SOG or not varies from place to place and the local instructions need to be read.

Logically speed through the water is the only thing that matters if controlling wake is the purpose of the limit, as blunt a tool as that is. However SOG is the only thing they can measure so in some places that is the limit.

On the Thames for example the limit is through the water from wandsworth bridge to teddington lock, and upstream of that the limit is SOG (and in kilometres per hour for good measure!)

Personally I just ignore all the limits and cause as much disruption as I can

 

[neale]

Why can they not go where it doesn't effect others for ****** sake?

I guess for the same reason that sailing races aren't staged where they won't affect others

 

[KINGFISHER 9]

It's a common problem in the small boat channel ... I suppose it's always a motor boat's fault because they cause the most wash, especially when sucking their sterns under at 7/8/9 knots, or whatever is the worst speed for it. It always amazes me that the people driving these things seem totally oblivious to what's going on behind them .. not difficult is it? Or do they subscribe to that good old British motto .. 'Why bother?' ... Maybe someone should design a sailing boat that leaves an enormous great trench in the ocean at 4 knots and we could get our own back! The other day I was passing port to port with a sailer coming the other way .. he was under sail coming out and I was motoring going back in ... we were passing about 10 yards apart, maybe less, when a Fairey Huntsman coming out behind this other boat suddenly got the thing up on the plane and went between us doing at least 20 knots .. I leaned over the side and called him a very rude name ... he probably wondered why but if I meet him on a pontoon anywhere he's going straight in the harbour!

 

[AlanRD]

Three points:-

1 - How is it speed limits don't seem to apply to Hobiecats (and similar) or windsurfers?

2 - Why do the 'authorities' not take action against those in question 1 who are speeding?

3 - Why do some Mobos regard the speed limit as a minimum, not a maximum? I know it is difficult for some to keep to a low speed but you often see smallish mobos nearly but not quite on the plane as they struggle to keep to the limit when by slowing down a small amount would make life easier for everyone and save them money and fuel.

 

[Elessar]

1 - How is it speed limits don't seem to apply to Hobiecats (and similar) or windsurfers?

they often do

2 - Why do the 'authorities' not take action against those in question 1 who are speeding?

Because they're probably not doing any harm.

3 - Why do some Mobos regard the speed limit as a minimum, not a maximum? I know it is difficult for some to keep to a low speed but you often see smallish mobos nearly but not quite on the plane as they struggle to keep to the limit when by slowing down a small amount would make life easier for everyone and save them money and fuel.

Who knows. Could be because the feel intimidated by boats astern, or because they're a bit selfish/stupid. Often better to speed up a bit in a small, light mobo but most they feel they can't break the limit.

 

[AlanRD]

they often do


Because they're probably not doing any harm.


I like that. I'll try using it if I get a speeding ticket in my car. Mobo drivers should also try it when there are no other boats near them. Somehow, I don't think it will work.

 

[BlueSkyNick]

Is this ...........Speed Over Ground, or Speed Through the Water?

I refer to Reeds Channel ALmanac 2009, page 120.

Speed limit is 10kn (through the water) within the harbour and within 1000yds of the shore of any part of the Dockyard Port.

Nothing about any type of boat having more difficulty maintaining speed than another. I guess it comes under the Stuff Happens category.

 

[Elessar]

I like that. I'll try using it if I get a speeding ticket in my car. Mobo drivers should also try it when there are no other boats near them. Somehow, I don't think it will work.

that's why I like boating and not driving - usually you get to use discretion and it's all the safer for it.

And in a mobo I exceed the speed limit. When it's safe and not inconveniencing others. It's very very rare when these conditions can be met in a 7 tonne boat, and usually the speed limit is too fast. In a small RIB or a dinghy though, the opposite is true.