Swim Platform

I am in the process of buying a 42 ft Grand Banks trawler. She is in excellent condition minus a swim platform that apparently got torn off the stern in some type of collision. Has anyone gone through the process of having a new swim platform purchased and installed? What is the ballpark cost of such a purchase?
We plan to do some scuba diving off the boat and a swim platform is crucial to that endeavor, and even hope that an extended platform can be installed to facilitate that hobby.

Congrats, maybe, on your potential new boat. Hope it works out for you. Yes there are companies that make swim platforms. We just installed an extended swim platform from swimplatforms.com. I don’t know if they make just swim platform ps or only extended swim platforms. You might ask them. We are very pleased with ours, no affiliation. It cost a bit less than $5K with shipping from Phoenix to Michigan.

Thank you sir for the referral and ballpark $$…The original platforms are teak on the GB’s but I would be interested in an extended platform in either Fiberglas or some other composite material. I plan on doing some scuba off the platform and want one with maybe an integrated fold out/ hide away swim ladder. Don’t want too extended, then I’m escalating to a larger slip and more $$
Comodave, how much real estate did you add to the back end?

It added about 2’. The platform is now 63” fore and aft.

I added a larger 28” platform to my GB42 from Butler Marine (butlermarine.com). Great product, great service. I think it was around $2k plus freight. But that was 7 or 8 years ago.

Bradenvlp - what is stock size of a platform on a GB42?

Holy bat boat Batman, that’s a tanning shelf for about half a dozen young maidens!!!

xxlcajun said:

I plan on doing some scuba off the platform and want one with maybe an integrated fold out/ hide away swim ladder.

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I installed one of these under my teak swim platform. I am very pleased with it.

https://www.osculati.com/en/11627-m-039647/big-under-platform-sliding-ladder

The swim platform extension came with an under mount 4 step ladder. Here is a photo of the black dog on the extension.

xxlcajun said:

I am in the process of buying a 42 ft Grand Banks trawler. She is in excellent condition minus a swim platform that apparently got torn off the stern in some type of collision. Has anyone gone through the process of having a new swim platform purchased and installed? What is the ballpark cost of such a purchase?
We plan to do some scuba diving off the boat and a swim platform is crucial to that endeavor, and even hope that an extended platform can be installed to facilitate that hobby.

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GBs have a few design flaws (as do all boats). The swim grid is one. Much too short. Not nearly robust enough. You now have the GB with an opportunity to have the best swim grid, and one designed with your diving hobby in mind!
Don't be afraid to go big.

My own boat had that GB design flaw, though not a GB. The SG started life at 22" deep. That isn't nearly enough, though still lots deeper than on a GB 42. I added 13" to get a 35" depth. After over 15 years, I am still very happy with 35", though I don't know if it would be deep enough for a lot of dive gear. I had a flip up ladder, so to fit the deeper SG I had it lengthened 6" and relocated to the new midpoint, where it still rests against the transom when flipped up.
The attachment bolts removed from the original SG were all corroded down to a fraction of their original diameter, so I learned from that and put all of the attachment bolts above the WL. Below the WL the supports are pressing against the transom Only the bolts higher up are in tension,

That would be perfect for scuba, usually there are 2-3 treads on a swim ladder, way too short for scuba use. Thanks for the link

Thank you Keith,
35 inches would be more than enough real estate for the girls to lay out, boarding, etc. Now that I’m thinking large platform, I’m thinking how handy a backup camera would be so as not to crush the platform against the dock or pier/piling. Why not use the technology readily used in the giant RV market? Or just the First Mate back there with a walkie talkie?

xxlcajun said:

..I’m thinking how handy a backup camera would be so as not to crush the platform against the dock or pier/piling. Why not use the technology readily used in the giant RV market? Or just the First Mate back there with a walkie talkie?

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Most times you should be able to see the edge of the swimstep by looking through the aft doors, or by standing outside the helm door while reversing in. Otherwise a camera could help. You may adapt to standing outside, facing rearwards, reaching to the gears to maneuver the boat, useful skill.

koliver said:

The attachment bolts removed from the original SG were all corroded down to a fraction of their original diameter, so I learned from that and put all of the attachment bolts above the WL. Below the WL the supports are pressing against the transom Only the bolts higher up are in tension,

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Well, this is true if you consider flat water and weight on the platform. But in waves, when the aft of the boat comes splashing down, the force of the water is applied upwards from the bottom of the platform.

We added a 12’x28” teak swim platform last year.
I bought the platform from Butler marine
Brackets from Great Lakes
I went a little overboard on the brackets. They’re heavy duty.
Zimmerman modified the brackets and installed the platform.

Swim Platform costs
Butler-swim platform. $2552.00
Great Lakes- Brackets. $516.00
Herrington- Haul out. $669.00
Zimmerman- install. $1454.00

Swim platform Total. $5191.00

xxlcajun said:

I am in the process of buying a 42 ft Grand Banks trawler. She is in excellent condition minus a swim platform that apparently got torn off the stern in some type of collision. Has anyone gone through the process of having a new swim platform purchased and installed? What is the ballpark cost of such a purchase?
We plan to do some scuba diving off the boat and a swim platform is crucial to that endeavor, and even hope that an extended platform can be installed to facilitate that hobby.

Click to expand...

I had a new teak platform made for my GB 36. An outfit in Florida had the template, made it up, and shipped it to me on the left coast in about 6 weeks. It's more robust than the original (thicker teak strakes) and fits on the same brackets. Try contacting Brad at Ventura Harbor Boatyard. He sourced it, and I never talked to them directly. If no luck, PM me and I'll do what I can to help. It was plug and play. I'm very happy with it.

Guilhem said:

Well, this is true if you consider flat water and weight on the platform. But in waves, when the aft of the boat comes splashing down, the force of the water is applied upwards from the bottom of the platform.

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Correct, but if your SG platform is an open grid of teak, as are all originals on the old GB that is the subject of this thread, that upward force is negligible, if it ever occurs.

Mine is 12" above the water, at rest, so when travelling at 8 knots it is getting wet with splash, but I have never seen any waves EVER try to lift it.

I often tie to a mooring buoy in front of my home, where there is a lot of traffic. That is where there are occasional waves from big boat wash, including commercial crab boats that always travel at full throttle, where their waves are bigger than those of the cargo ships coming by, and sometimes those waves come at the boat from the stern. Even then, I have never seen my SG getting wet from them. The best test of that, is the "welcome mat" that I have on the top surface of the SG to deter otters from setting up their kitchen table and toilet on my boat. It has seen the whole gamut of wave action and never gotten wet.

Make your own

Wood shop experienced or find a woodworker. We epoxied up marine ply, clamped, cut and routed. Stained with a supposed to look like teak. Ground walnut for traction.
Fiberglass skills? Base layer matte fiberglass and then 6oz. Use UV surfboard epoxy resin like Resin Research.
You might find a surfboard glassing company to to a side job.

Second on Butler Marine. Top notch service and quality.

For diving, you will want a ladder with a central pole so you can use it with fins on. We have used Windline DL Sport / Diver Boarding Ladder - 4 Steps on both Fintry and Morning Light. It is removable and comes with brackets to store it on a bulkhead. On both boats we mounted the attachment on a heavy stainless hinge, so we can just swing it up out of the water when underway. We take it off only for long passages. Highly recommended. We got ours from Defender, but many others also sell it.


Jim

Swim Platform for 42 ft Grand Banks

I just got a quote from Butler Marine in PA for a new teak Swim Platform for my 42 ft GB, About $2750 incl delivery.

I've been scuba diving off mine for the last 10 yrs but I'm planning to sell mine next year. Let me know if you are interested in a scuba compressor for your boat. I have a RIX 6 cfm with a Honda gas engine drive and 2-long high pressure hoses so tanks can be filled at stern with compressor on the bridge.
Can send photo and details. My boat is currently in Cape May, NJ.

I also have a dive ladder that is heavy enough for a diver wearing doubles.

Reveille said:

We added a 12’x28” teak swim platform last year.
I bought the platform from Butler Marine
Brackets from Great Lakes
I went a little overboard on the brackets. They’re heavy-duty.
Zimmerman modified the brackets and installed the platform.

Swim Platform costs
Butler-swim platform. $2552.00
Great Lakes- Brackets. $516.00
Herrington- Haul out. $669.00
Zimmerman- install. $1454.00

Swim platform Total. $5191.00

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I agree with the entire over-built brackets. I had a GB42 classic and back in 2001 rebuilt the swim platform after the previous owner had backed into something. The repair was out of mahogany and IPE since I could not source the teak at the time. It matched perfectly. But like others have stated the swim platforms were underbuilt by American Marine Ltd. Ken Smith penned a great all-around coastal cruiser that went on to become a legend and a benchmark in the industry, but aesthetics were possibly more important to him than function.

I now have a Cheoy Lee 34 Pilothouse Trawler and it has a full beam x 30" rock-solid FG swim platform with high, super stout (removable) SS railings (think an early form of staples). I had much rather add this HD swim/dive/cookout/entry platform to my old GB42 than what I had. It is often the first thing folks feel underfoot when boarding from a dinghy or when berthed astern. That solid-as-a-concrete foundation comes from not only thick fiberglass, but more than double the support brackets in size and number needed. Highly recommend it after having both.

We just received our new teak swim platform from Butler Marine for our DeFever 41 - we more than doubled the size to 48 inches deep to accommodate our Hurley Davits. Our boat will be pulled from the marina this week to install. We couldn't be happier.

+ 1 for Butler Marine

radbriley said:

We just received our new teak swim platform from Butler Marine for our DeFever 41 - we more than doubled the size to 48 inches deep to accommodate our Hurley Davits. Our boat will be pulled from the marina this week to install. We couldn't be happier.

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When I installed my extended (to 35") teak Swimgrid I didn't need to haul. The old SG supports were too light weight and 13" too short, and when I pulled them off, the SS fasteners were corroded down to almost nothing where they passed through the transom. I used caulking in the old holes to keep out the water until my next haulout a few months later, when I fixed those holes properly.
None of the new holes were below the waterline, as that part of the supports is not in tension, so the fasteners above the WL could do the whole job, and I saved waiting or doing an extra haulout.