Swimplatform submerges

[Njlarry]

My 400 Sedan bridge has an extended hydraulic swimplatform that extends about four feet. Often times it is awash with water splashing up and forward over it as the picture shows. Is this normal or cause for concern? Once up on a steady plan it is up out of the backwash.

 

[Strypes]

Interesting. Subscribed.

 

[Gofirstclass]

When we first bought Beachcomber 10 years ago I had a large swim platform built for it. We loved the size but it became a PITA. When we would come down off plane water bubbled up beneath it, causing it to submerge and to flop up and down so much it broke the mounts.

We ended up cutting it off and I had another built that was much sturdier, didn't flop around and didn't submerge, The one below is the first one that was put on,

 

[FootballFan]

I would say that is excessive. Something is not correct. I had a couple of hydraulic swim platforms, never saw anything like that.

 

[Stee6043]

Well....that is why they install those vents in the platform!

Can the upper limit on your platform be increased?

How's the boat running overall? Does it get on plane pretty easily?

 

[Carver370]

I would say that’s pretty normal for a diesel 400 Sedan with a huge heavier than normal platform.

The factory non hydraulic platform on two my friends 400 Sedans does the same thing at plowing speed. Even my 400 Sundancer will if you run around 12-14.

Try putting your tabs all the way down at the same speed and see what happens, it seemed to help on all of the above.

Both my friends have learned to power up quickly and gradually come off plane to the point it would be awash and then bring them down quickly. The transom and platforms on these boats are very low.

 

[copb8tx]

If the platform comes all the way up and level with the deck and your boat doesn't have any hull water intrusion that would have it sitting lower in the water than designed then there's really nothing that you can do. I assume the platform is a above the water at rest?

 

[Gilberto Beato]

Good morning, all,
I'm new to this group and I joined because I need help!!
I have a 2008- 330 Sundancer, and swim ladder broke and I'm trying to replace them, I got the bracket bolt loosed but cannot get them out. I cannot find a way to reach to them, any suggestions?

 

[Irie308]

In certain sea conditions at trawling speeds I see the same, but as stated that's why they have vent holes. I have the option of raising the platform another 3-4 inches. Not sure if it would make a difference but considering it over the winter.

 

[dtfeld]

Not sure what rpm/speed he’s running at, but possibly pull it back a little. Hull speed is in the 7.5-8 kit range for these boats, adding more power only produces more wake, burns more fuel, very little extra speed. Just a small reduction in power makes a big difference in wake/wash on my boat.

My 410 (which has a very similar if not identical hull) is happiest about 950 RPM, 7.5 knots. Beyond that I get a similar result.

Tabs down on my boat at these speeds doesn’t produce any noticeable lift, but does cost about .3-.5 kts.

 

[JimG]

Good morning, all,
I'm new to this group and I joined because I need help!!
I have a 2008- 330 Sundancer, and swim ladder broke and I'm trying to replace them, I got the bracket bolt loosed but cannot get them out. I cannot find a way to reach to them, any suggestions?

You need to start your own thread for this... don't hi-jack this one.

 

[jzanthony]

Mine does the same thing, i have to be gentle coming off plane or the ladder door will flip open. 1200 to 1400 rpm its seeing alot of water 1100 and lower seems to work ok.

 

[Skybolt]

Mine also does the same thing ~10 mph, as mentioned there are vent holes to relieve the water pressure. I don't see it as a big deal.

 

[Njlarry]

Well....that is why they install those vents in the platform!

Can the upper limit on your platform be increased?

How's the boat running overall? Does it get on plane pretty easily?

Upper limit is not adjustable but will look at it in the fall to see if hardware mods could raise it but not much room and still be with the lines of the boat hull.
Boat accelerates fine but wot only 2600. I have to consider having the timing and injectors serviced but wot in neutral is 3100 so I quess more likely a prop issue?

 

[fwebster]

The real problem is the 400DB is a stern heavy boat. In the best of conditions while 350hp Caterpillars are great engines, that power for the 400DB is marginal , 300hp Cats is underpowered. When the 400DB was introduced it was a hot seller and a lot of dealers put existing customers names on the new boat order forrm to secure a boat for inventory. To keep cost down they ordered the 300 hp engines and now, as those boats enter the secondary market we have a new group of stern heavy owners.

We had 4 400DB's at one time in our marina and I watched the owners add 3000# of hydraulics & oversized platforms and 1200 # jet skis to them then spend a ton of money trying to cure a general design issue of being stern heavy. The most workable solution I saw was to change the bow anchor to an all chain rode from a nylon rode. Unfortunately, while that helped the stern heavy issue it also added several hundred lbs of weight right in the nose of the boat which slowed performance and increased fuel burn.

This may be a problem you just have to learn to live with………


Frank

 

[Creekwood]

My 400 Sedan bridge has an extended hydraulic swimplatform that extends about four feet. Often times it is awash with water splashing up and forward over it as the picture shows. Is this normal or cause for concern? Once up on a steady plan it is up out of the backwash.

I recalled that a friend of mine had that issue when he upsized his dinghy on a 560DB. He also had a droop to his hydraulic platform. Here is the thread of what he did. When I open the old thread I see grayed out images from the old Photobucket pictures. You can see enough to get the idea of what he did. It worked perfectly as I recall.
http://www.clubsearay.com/index.php?threads/dingy-on-a-560.21338/

 

[Njlarry]

Thank you for the very helpful link. My platform clears the water by5 inches at the aft end and is 3.5 inches below the cockpit deck. Off season nowplan to add 3x3 aluminum stock to gain a little more clearance.

 

[Njlarry]

Guessing Tolechester?

 

[Njlarry]

Any breezes or hot as Haiti?

 

[Creekwood]

Thank you for the very helpful link. My platform clears the water by5 inches at the aft end and is 3.5 inches below the cockpit deck. Off season nowplan to add 3x3 aluminum stock to gain a little more clearance.

One thing to note is that we are in fresh water, so aluminum mounted to stainless is not a concern. You are in salt, so you probably want to do something to separate the metals in some way if the arms of your platform are stainless steel. If they are aluminum all should be fine.