Swim deck and added weight scr3300

[Toolboat]

I’m thinking of building an extended swim platform for my scr3300 how much weight can I put on the back without killing performance? Has anyone built a platform that extends the factory one ? The commercially available ones go over the top of the factory one. I would love to be able to carry a stand up jet ski back there.

[shrew]

Originally Posted by Toolboat

I’m thinking of building an extended swim platform for my scr3300 how much weight can I put on the back without killing performance? Has anyone built a platform that extends the factory one ? The commercially available ones go over the top of the factory one. I would love to be able to carry a stand up jet ski back there.

A jet ski that far back will make getting up on plane an ordeal. Just having a few adults sitting on the transom seat used to make it difficult to get my 2800 up on plane.

[XBS]

I actually just purchased the davit system from dinghy davits.com and plan to purchase a Sea Doo spark (400lbs) to attach to the back of my 3300SCR w/ 5.7s

I currently get on plane rather easily with a 8.5' hard bottom dinghy. I am planing to relocate the batteries forward as well to balance the weight of the boat better since right now it leans on the port side and this will move a lot of weight forward (maybe under front bed, convert that area to battery compartment.

[2004_3300_SCR]

@XBS keep us posted with your install progress! I have the same model boat / power package.

[XBS]

Will do, the Davit system just came in. Now I need to find someone with a SeaDoo Spark to see how the weight handles on the back.

[Foxy 01]

I had one built for my 35' Maxum. The factory one was far too expensive. It made access far easier the only thing that had to be moved was the swim ladder. Used to carry a dinghy that weighed about 80lb. made no difference to the performance. I think a jetski might kill it with that sort of weight.

[XBS]

Hi,

Thanks for your reply, the Sea Doo Spark weight about 430 pounds, so about 300 more than my current inflatable.

Will that much weight really make a difference on a boat that weighs 15,000 lbs dry?

Which extended swim platform company did you go with? I appreciate your feedback!

[Foxy 01]

At the time i had the platform fitted the boat was in Sydney. I just sent it to one of the marina companies and they made up a fiberglass template of the platform and molded it flush underneath the existing platform and supported it with several stainless support bars. Certainly not factory approved as the factory one over here was priced then at $15.000US. The main reason i had it fitted was to make it easier to access the dinghy as the existing platform is quite high and thus getting on and off was a breeze. I really don't know how your boat will perform with all that weight on the stern it seems to me a massive change in the centre of gravity. You may have to move a corresponding weight forward near the bow or alter the trim tabs. Anyway, the best of luck hope it works for you.

[Phillbo]

You will be disappointed....That is a lot of weight.

[XBS]

Well I bought a used 2014 Spark 2UP and used my existing weaver Davit’s that were already in the boat and added the dinghydavits.com system.

Going to finish securing the Sea Doo before a sea trial. The water mine at the front of the boat went up about 2”. Going to re-locate batteries to front bow under bed (new lithium setup removed generator) and also add more chain in the locker to balance out the boat.

I hope this helps anyway else out there as crazy or illogical as I. Will report back after it’s secured and some sea trials.

What do you guys think of keeping the fuel tank and fresh water tanks full to help offset rear weight (438lbs dry)

[shrew]

Steel chain won't be enough weight (or it will be too bulky. Look at reclaimed lead for ballast.

[2004_3300_SCR]

Thanks for the pics, that looks great! Just my opinion based on a couple of months running the same boat, but I think you're going to be fine. This past summer I had easily 600# of siblings sitting in the seats just fore of the transom, plus several other passengers aboard, 3/4 tank fuel, near full water in holding and 1/2 a tank of blackwater, and we planed out/handled just fine. Believe we have the same 2bbl 250hp Merc 350s on Bravo 2 drives. COG distribution for you is a couple feet more aft compared to my sibling ballast and cantilevered over the transom underwater, but also less weight. If you're bow high I'd imagine you'll be able to trim it down, but with the other weight distribution changes you're doing I'm thinking you'll barely even notice a difference. Looking forward to hearing how it goes.

[XBS]

Thanks for the replies. I am going to look into adding some lead ballast under the dinette since my boat has always leaned to port when sitting in the marina (even after removing the generator which was on port side, but still isn't level)

My idea is this will help offset the weight of the sea doo (let's say 500# with fuel and fluids) and also bring some balance back to the boat.

We changed the trim tabs last year to the largest possible we could fit on the hull and the boat planes very easily now, so I think worst case Ill just have to trim more to plane.

Mine is a 2000 with the 350 MPI engines and brave 3 outdrives. I am not sure of the horse power rating but I recently replaced everything on them, including all 16 injectors, so she runs like new! I can get to about 40 mph on the GPS in ideal conditions.

[XBS]

I was able to secure the sea doo and take the boat out this weekend, good weather and a lot of people out so it was choppy enough to test everything out.

I had a little over half a tank of fuel, was by myself, and was able to plane multiple times with out issues.

If I didn’t use the trim tabs it takes longer of course but I don’t have the 7.4s.

So far so good, now working on new fuse blocks on some other electrical issues

[2004_3300_SCR]

Nice! Thanks for the report back. Figured you'd be good, especially with the more effective B3 DP drives and 100 more HP than mine.