2004 366 Aft Cabin Swim Platform Waterline

[Daysawasten]

We're trying to figure out if the waterline of our swim platform is normal for our model boat.

We purchased a new to us 2004 Carver 366 Aft Cabin MY at the beginning of this year. The swim platform water line is MUCH lower than the platform on our previous 325 Aft. Without adding anything the swim platform was just a couple of inches above the water. This seems to be by design, and perhaps due to the engines Volvo Penta D-6-310s (our boat survey says "this is one of the few boats fitted with the diesel 310 HP Volvo with electronic controls and a bow thruster" - I only mention this because it may add to the overall weight). We've been asking around and the only theory that makes a little sense is that the hull was designed for lighter gas engines and our boat has the heavier diesels.

We finally got around to installing a Weaver Snap Davit for our 9' inflatable and we added a Weaver Motosto for our Nissan 9.9 outboard. So, we've added maybe 200 lbs to the swim platform, and now the platform is just about touching the water. In fact, when you stand on the platform is does touch.
Note : this is with empty water tanks and fuel tanks at 3/4

Has anyone else had this problem? If so, what did you do to remedy the situation. We're thinking of adding ballast forward? Any remarks or suggestions would be appreciated.

Thanks

[buster53]

Yes, the extra weight of the diesels has a definite affect. What about the aft fuel tank? I know the 356 has one, I assume the 366 does as well. Is it full?
About adding weight to the bow, nothing about that idea makes sense. Removing weight or shifting weight does.

[hargsnz]

I have a new to me 2003 366 with twin Cummins 280HP they are 5.9 litres,each so maybe not much difference in weight to yours I think. I have an 8KvA Kohler in front of the engines. My platform was probably only about 6" above the water when I got her and the boat looked stern down, I don't have a heavy dinghy, I swapped my RIB for one with an inflateable floor mostly because at my age I wanted something lighter to pull up .
The fuel tanks run length-wise.
I believed mine was too light in the bow in any case & so I've added an extra triangle shaped flexible water tank in the front & I believe mine sits much better in the water as a result. Also my wife likes the extra water.
The boat looks much better sitting in the water & the painted waterline is still above the actual waterline so I'm happy with that.

[Daysawasten]

Thanks Hargsnz. Your model is closest to ours and sounds like you had the same issue. The swim platform on our previous Carver (1996 325 Aft) was a completely different design & sat high out of the water. Not sure what thinking was when they redesigned the hull with that low low low platform. Only thing about our boat I don't love. Where exactly did you place your flexible water tank?

[Lyndon670]

All of the MY designs from 1999 (99 for the 506 and 2000 for the rest of the MY fleet) and onward are all like this. When I purchased my 506, I spoke with a Carver engineer who advised me that this was designed like this to have a more effective trim situation - in otherwords, the platform is part of your planning surface. It is a very effecient hull design.

If you look across the Carver MY spectrum, you will see that the MYs are all the same with this design.

My platform submerges around 10kts and pops back up around 12kts as the boat levels out.

The downside? Major wave noise in the aft stateroom. Anything more than a chop and you will hear the constant chop.

[SplashyLady]

You could install a flotation pod under the platform. It's just a large, air-filled box that installs under the swim platform and raises the boat up at rest. It can also help with putting the boat on a plane (if you do that). These are pretty popular with smaller boats when owners put bigger outboards on the transom to offset the added weight.

[Daysawasten]

Lyndon370, Thank You for the explanation re: this hull design. Good to understand the reasoning. I guess we just need to get used to the platform being so close to the water & as you say submerging at lower speeds.

[hargsnz]

Source of the post Thanks Hargsnz. Your model is closest to ours and sounds like you had the same issue. The swim platform on our previous Carver (1996 325 Aft) was a completely different design & sat high out of the water. Not sure what thinking was when they redesigned the hull with that low low low platform. Only thing about our boat I don't love. Where exactly did you place your flexible water tank?

I put the water tank in through the hole in the galley area. It pushes right up the front of that space which is a triangle due to the steps. As the tank is a bladder triangle it fits in quite nicely & will connect through a 'T' into the blue water line which runs to the main water pump which is also in there. I put a tap there, but it's not really needed. The good think is that in that particular space it fills fully from the main tank & empties automatically. The bladder tank I got had tabs on each corner and the floor has some existing wooden chocks on the floor which it fitted into & I just used a big washer & simply screwed the tab onto the floor.

[hargsnz]

Source of the post All of the MY designs from 1999 (99 for the 506 and 2000 for the rest of the MY fleet) and onward are all like this. When I purchased my 506, I spoke with a Carver engineer who advised me that this was designed like this to have a more effective trim situation - in otherwords, the platform is part of your planning surface. It is a very effecient hull design.

If you look across the Carver MY spectrum, you will see that the MYs are all the same with this design.

My platform submerges around 10kts and pops back up around 12kts as the boat levels out.

The downside? Major wave noise in the aft stateroom. Anything more than a chop and you will hear the constant chop.

Yes, the "swoosh / slap" noise up the stern at night takes a little getting used to. But I try to anchor where there's no roll at night. I think that the very generous beam on the 366 also contributes to the potential for slap.

[unsubscribed]

hargsnz,
I’m considering a Carver 366 MY and looking for dinghy ideas. What size, what kind, mounting options. The swim platform is pretty narrow and would be restricted with ropes or brackets. I can’t seem to locate picture of examples of mounting for this model boat. Please help.