Rocking problems on Bertram 28 Flybridge

[fonsim]

Hi guys

Did you guys have rocking problems when anchor? They move more than other boats. Any suggestions?

[Carl]

cough cough...

...rocker stoppers ?!?!




Deep V's rock, no if and's or butts about that.

They run solid, steady and straight in sea's, but you pay for that when drifting or at anchor if your nose isn't into the sea.

I have found sometimes turning the rudders can help direct you into the oncoming sea or deploying a sea anchor "can" help as well.

Trick is to keep the bow into the waves...down side is when it blows, it tends to push boat sideways and sideways is not your friend.


A full tank of fuel and water help as does lighten up the bridge...you want as much weight centered and low as possible.
But in the end...Deep V's ROCK

[Yannis]

Aaaahaha!

Welcome to the disco!
Is it enough if I told you that I was moored at a dock , tied up normally, and in the middle of the night I fell on the floor? From the (improved) dinette bed? I heard a thump noise and it was...me on the floor!
Too much dead rise, most weights on either side and this is what you get.
There is a product that you hang on the sides that limits the rocking (3disks, spaced every 30 cm approx, on a common rope that passes through the center of the discs). I forget the name. Or hang two buckets, one on each side, with a heavy weight inside them.
Don't invest into a tower!

[fonsim]

Thanks, I think to put the batteries in the center of the engines too for the weight. Did someone tried before?

[Yannis]

Its all wet down there, you have to put them in a waterproof box or else they’ll ....float!

[Carl]

There is a product that you hang on the sides that limits the rocking (3disks, spaced every 30 cm approx, on a common rope that passes through the center of the discs). I forget the name. Or hang two buckets, one on each side, with a heavy weight inside them.

Rocker Stoppers is the product.

If you do a search on the old site it will bring up a very long, well and not so well debated discussion on the topic.

Long story short...Deep V's Rock.

We used to hang out on the docks, BBQ and bend elbows frequently...all the boats could be steady in there slips and mine would be rocking away.

[Yannis]

Yes, Carl, I’ve read all this in the past. Still, I haven't bought those rocker stoppers...
Like you said, we’ll rock forever!

[David Davidson]

http://www.quantum-medmarine.com/

Overkill?
Nah!

[Carl]

http://www.quantum-medmarine.com/

Overkill?
Nah!

Those come int effect when your moving and cruising and we don't need them then. Deep V's run great...its when stopped we suffer.

Now a Gyro stabilizer might work just fine...but coughing up 20k for the unit plus a whole lot more dough-ray-me to attached unit securely to boats hull has me feeling woozy.
Actually I don't know the cost today,,,just trying to recall from a few years ago.

https://www.powerandmotoryacht.com/main ... -your-boat

[fonsim]

Its all wet down there, you have to put them in a waterproof box or else they’ll ....float!

Yep

[David Davidson]

"Those come int effect when your moving and cruising and we don't need them then. Deep V's run great...its when stopped we suffer"
Carl, they are "zero speed" also (i.e. at anchor) and they work very well....but it was a joke.

[Tony Meola]

Please lets not get into the Rocker Stopper debate again. That was historic.

The 28 tends to rock more than the 31 due to the higher center of gravity. On the 31, no tower, I find that the rock is not really that bad while anchored unless some Yahoo comes speeding by within 10 feet.

Offshore drifting, depending on the seas, it can get squirelly, Once the 31 is up and running, I have found even in a beam sea, she is not bad. I think the 28 is a much better head sea boat than the 31. There are trade off's for both models.

Keep your weight low and centered. Batteries in the center of the bilge help. In a good box. You can build one easy enough.

Center up as much weight as possible, it will help. If it is still bad, before investing in rocker stoppers, try hanging a couple of 5 gallon buckets off the center cleats. Drill some holes in the buckets so they will drain. See if it helps, that would simulate the god forbid Rocker Stoppers.

[Yannis]

Tony,

The 28 center bilge is wet. All water from the deck, filters down there eventually UNLESS you have put in place a draining system/method that prevents it. Easier said than done!

Whether it be because the hatches' drain holes are small, or because they are sometimes clogged, or because the hatches' lip seal is not waterproof (or is difficult to render waterproof), or because (unlike the 31) the engine hatches are also draining to the same spot, anyway for a number of reasons, that area is always wet. Not so much underway when water is pulled aft and pumped out by the aft pump, but at rest the non pumped water is brought back into the center bilge area. If you combine all this with fishing, this leads to that water being also dirty with blood or gut remnants...

So, if one is to put the batteries in there, I would think that just a waterproof box sitting on filthy water is perhaps not the best solution. What I would do, which I haven't yet done, is that I would make a removable rack/grill that would NOT be just sitting on the hull, rather a SS rack that would be HANGING from the stringers on both sides and would be low enough to provide for low center of gravity, yet high enough so that the bilge water is well clear under it. That way, the battery box that sits on it will not always be contaminated by bilge water and the rack itself would be thought-out in such a way so as to leave enough space to reach and to clean the dirt underneath. In my case with 4 batteries I believe this is almost impossible to do, but for up to 2 or 3 batteries this is maybe easier because it should leave room to stand on the bilge and somehow be able to wedge a broomstick under it to clean. And also watch the bilge pump and be able to service it etc.

Anyway, just because this is a difficult project, I have left it undone so far and made friends with the idea that rocking and rolling is a... good thing ha ha!!

[Carl]

Yannis- - in my boat the batteries sit on a shelf that bridges across the center V.
It is a good 5" off the bottom so water easily flows under. Shelf sits on small tabs I glassed in at the center set of stringers, then glassed shelf to stringers and tabs.
Simple and solid, holds 3 batteries, low and centered.

[Yannis]

Carl, so I thought I could have made a discovery but hell, someone got there before me! Lol !
Still I would want that shelf to be removable tho...no big deal, the principle is the same!

Question: in case you want everything removed from down there, batteries and shelf, so as to repair or change pumps, or through hulls etc, are the battery cables LONG enough to be able to displace batts without having to disconnect them? Just curious!

[fonsim]

Yannis- - in my boat the batteries sit on a shelf that bridges across the center V.
It is a good 5" off the bottom so water easily flows under. Shelf sits on small tabs I glassed in at the center set of stringers, then glassed shelf to stringers and tabs.
Simple and solid, holds 3 batteries, low and centered.

Carl, can you post some pictures of it?

[Carl]

Thinking about it, the tabs are glassed and the shelf is removable (screwed into tabs) and might be even lower.

I have shelf all the way back to bulkhead, its in line with transmissions and starter making those heavy duty cable runs short as possible. Battery switch sits right over with isolator and have a cover that protrudes and covers switch.


Next time I'm down I'll take a pic...thats IF it ever stops raining.

[fonsim]

Thanks Carl

[QUOTA2]

The 28's are rockers but a nice ride to bad Bertram didn't put maybe a small keel like the 35's wonder if it would have made a difference. Have a fishing buddy that will rock away and be fine but once I move her you don't want to be down wind over the side, go figure.

[Carl]

The 28's are rockers but a nice ride to bad Bertram didn't put maybe a small keel like the 35's wonder if it would have made a difference. Have a fishing buddy that will rock away and be fine but once I move her you don't want to be down wind over the side, go figure.

I'd have thought heavier chines or widen over a keel to reduce rocking.
Or widen with chines.

[Tony Meola]

Carl


I think wider chines on both the 31 and 28 would have made a big difference in the role.

[Tooeez]

When I bought my 28 it had two group 29 batteries between the engines sitting on a shelf glassed to the bottom. They sat in about an inch of bilge water, and the boat rolled like a beast. Now I have four group 31's, two on each side, outboard of the engines. The weight and position change made absolutely no difference; still rolls like a beast. I'll take the roll over a pounding ride every time.
By the way, I knew someone who ran charters on a 28 bahia mar. He had the rockerstoppers, and said it made a huge difference.