flooding hull on searider

camtheribman · 16 July 2009, 22:11

hi,

Is it worth blocking up a hull on an sr4? i will just be razzing about and going cruising. I have been given lots of different answers and want to know what is best.

Cheers

Downhilldai · 16 July 2009, 22:12

Try it both ways and decide which you prefer.

JSP · 16 July 2009, 22:13

Go make a coffee and do a search on the subject. Most agree blocking them off is best.
Haven't tried mine blocked off yet.

camtheribman · 16 July 2009, 22:19

okay, i will do that.

cheers

Rogue Wave · 16 July 2009, 22:22

if you are not going to dive or fish then I spose you could block it off. I like em left open

camtheribman · 16 July 2009, 22:24

Quote:

Originally Posted by Rogue Wave

if you are not going to dive or fish then I spose you could block it off. I like em left open

dont plan to do any of those. but i will leave it open for a while i think

Nos4r2 · 16 July 2009, 22:35

Quote:

Originally Posted by camtheribman

dont plan to do any of those. but i will leave it open for a while i think

I reckon it works better with it open on a 4m-but blocked on the 5.4

JSP · 16 July 2009, 22:39

grumble...moan...7 kids...grumble...moan..wish I'd blocked mine off years ago...grumble moan

Rogue Wave · 17 July 2009, 12:49

Quote:

Originally Posted by camtheribman

dont plan to do any of those. but i will leave it open for a while i think

you'll love the holeshot with them left open

donegaldan · 17 July 2009, 13:03

Took my SR4 from north west corner of Donegal to port ellen couple weeks ago, stopped half way for a cup of tea that could not be beat. Would have been thrown around like a cork had i blocked them off. The stability of the flooding hull let me sit beside a 6.5 no issues. The rest of the time, i spent in the air ! :-)
Donegal dan

camtheribman · 17 July 2009, 13:28

Quote:

Originally Posted by donegaldan

Took my SR4 from north west corner of Donegal to port ellen couple weeks ago, stopped half way for a cup of tea that could not be beat. Would have been thrown around like a cork had i blocked them off. The stability of the flooding hull let me sit beside a 6.5 no issues. The rest of the time, i spent in the air ! :-)
Donegal dan

sounds like fun, i can see the advantages now

chewy · 17 July 2009, 13:54

I've left mine open seen as its going to be left on a mooring.
Might do the odd spot of fishing on it too.

If you leave it open least you don't have to worry about your blocked off hull leaking!

camtheribman · 17 July 2009, 14:57

Quote:

Originally Posted by chewy

I've left mine open seen as its going to be left on a mooring.
Might do the odd spot of fishing on it too.

If you leave it open least you don't have to worry about your blocked off hull leaking!

that is very true,

my mind has been made up, thank you for all your help everybody

HUMBER P4VWL · 17 July 2009, 15:13

Sorry guys I'd veer towards blocking it off. Owned a 5.4 for 12 years and spent 3 with it open. The decision I think lies with two elements

1. The percentage of time you spend getting on to the plane. If you cruise, once the water is out it is out, so no problem, then at rest it is more stable. However if using as a rescue boat, constantly stopping and starting....block it up!

2. How is stability compared to transom height. We had ours on a mooring and the famously low transom meant with a flooded hull waves will slap over. The back if tide and wind are opposite. Same token when fishing. Waves lap over and with no sink at the back of the deck, you are always in water. Fine if in dry suit or skiing etc not so good for family days out or fishing.

Horses for courses, just try both. I found no real difference in stability as tubes are on water anyway if blocked up. However it was drier and quicker on to the plane.

Many threads on this that usually end up with blocked off being better... Unlike this thread so far!

Nos4r2 · 17 July 2009, 15:24

Quote:

Originally Posted by HUMBER P4VWL

Sorry guys I'd veer towards blocking it off. Owned a 5.4 for 12 years and spent 3 with it open. The decision I think lies with two elements

1. The percentage of time you spend getting on to the plane. If you cruise, once the water is out it is out, so no problem, then at rest it is more stable. However if using as a rescue boat, constantly stopping and starting....block it up!

2. How is stability compared to transom height. We had ours on a mooring and the famously low transom meant with a flooded hull waves will slap over. The back if tide and wind are opposite. Same token when fishing. Waves lap over and with no sink at the back of the deck, you are always in water. Fine if in dry suit or skiing etc not so good for family days out or fishing.

Horses for courses, just try both. I found no real difference in stability as tubes are on water anyway if blocked up. However it was drier and quicker on to the plane.

Many threads on this that usually end up with blocked off being better... Unlike this thread so far!

I'd agree with you on blocking it off on a 5.4, but the 4 is a totally different beast.
The power/weight ratio on a 4m is usually so high that with it unblocked it'll point the bow upwards then just shoot up and flop down onto the plane.

HUMBER P4VWL · 17 July 2009, 15:33

Fair point, never been on a four!! So can't comment. Bet they are great fun. Miss the fun of our 5.4 to the new boat.

JSP · 17 July 2009, 15:36

Quote:

Originally Posted by Nos4r2

I'd agree with you on blocking it off on a 5.4, but the 4 is a totally different beast.
The power/weight ratio on a 4m is usually so high that with it unblocked it'll point the bow upwards then just shoot up and flop down onto the plane.

Yeah, they just shift regardless. With the amount of water a 4m hull takes in is nothing anyway.

As for the 5.4m, there are good and bad points. The good points and bad points have been listed in lots of threads. Only thing I can add is with the hull open they seem to come off the plane at higher speeds when in the rough. I could be wrong on this but a few times I've had to back off on the throttle when things have got to rough and have struggled to keep it on the plane at speeds above what it normally planes at. This could have nothing to do with the flooding hull but I'm sure it would be better with it bunged.

Searider · 17 July 2009, 21:40

Have had 3 Seariders:

4m Deluxe with 50hp Yamaha. Tried it open and also blocked. Helped getting on the plane with it blocked when 4 persons in the boat, but, stability at rest was poor and the Avon blanking kit leaked - so after a couple of days afloat I was lugging the extra weight around anyway. I think my problem was a propeller that had too big a pitch.

5.4m with a 90hp Mariner. Never bothered trying it blocked and never felt "when will the water drain out". I think that with a 5.4m with plenty of power it's probably best left open. Low transom freeboard though as has been mentioned above.

4m (current one) with a 30hp Yamaha non-electric 2 stroke (light!). Un blocked and goes like a hooligan. Even with a couple of adults and a few kids it gets up and goes. Boat is left afloat all the time so not practical to block off and risk leakage.

The only time that i've "felt" the weight of the water in the void is when going flat out from a standstill. If you throttle up to 7 knots or so - the water will be clear of your transom and the void draining out anyway. Then gun it.
So, I think that with thoughtful driving it's not an issue.

Who does a flat out take off in their car on a regular basis?

Poly · 27 July 2009, 20:06

Quote:

Originally Posted by HUMBER P4VWL

1. The percentage of time you spend getting on to the plane. If you cruise, once the water is out it is out, so no problem, then at rest it is more stable. However if using as a rescue boat, constantly stopping and starting....block it up!

In my experience sailing club rescue boats spend a lot of time sitting in the water going no where (stability of flooded hull preferred); a bit of time moving around relatively slowly (no real issue with a flooded hull) and occasionally need to go at WOT to get to a rescue.

But given the choice of sitting bobbing about like a cork for a few hours so that the one 5 minute blast that day is a little quicker or sitting comfortably for hours and putting up with taking an extra 5-10 seconds to get to the "rescue" I know which I would choose.

It is also presumably easier to get a casualty on board a "partially-sunken" sea rider. And in choppy conditions the crew will be in better shape as well as working on a more stable platform when alongside the "casualty".

tim2658 · 27 July 2009, 20:50

after reading about blocking off the hull for months i was still debaiting it, then this weekend i left my 5.4 at anchor all night while we camped on the beach and she had so much water in her, i could sit and watch it slaping over the transom,so this week i will block her up and will measure how much more freeboard it gives you on the transom.