1985 SUPER SPORT 15: where to mount swim platform

[davidB01]

Q1: when mounting a swim platform on the transom of a 1985 SUPER SPORT 15, what basis determines if the platform mounts on the Port side or on the Starboard side?

BACK STORY
I plan to install Martin Marine swim platform and ladder on the transom a 1985 SUPER SPORT 15, as seen in the photo linked below, which shows a port-side mounting.

http://www.martinmarinedesign.com/images/products/313.png

Ray (of Martin Marine) told me the platform can be mounted on the port or starboard side of the transom by switching the two rails. He says it will work equally fine on both sides.

SUMMARY OF SEARCH RESULTS FOR INFORMATION ON THIS TOPIC
I have searched for every picture and thread I could find on mounting a swim platorm to the transom, including the really detailed and excellent threads by Tom Hempell on his 16-footer POW’s rebuild, schuyler84’s modification of his 1988 15 SS, and DTMackey SS 15 rebuild. All have been extremely helpful. My three searches combined produced about 75 different threads to learn from and to be inspired by

All but two the pictures I found show the swim platform on the Port side of the transom.

I need to decide if I want to relocate the battery and fuel tank to the starboard side to help balance out the weight in the boat. Most of the time only an operator will be on the starboard side. Moving both a fuel tank and a battery would shift 75 to 100-lbs to the Port side, but that would take up most of the free space to step into the boat if coming up and over the swim platform. Hence the question on if I should, or I should not install the swim platform it to the starboard side, which would then be basically empty.

[Phil T]

Many owners have relocated their fuel tanks and batteries to amidships.

Strongly consider relocating fuel tank to underneath the forward bench seat and the battery to underneath the console.

[davidB01]

Thanks Phil. I saw this earlier, but forgot to thank you for your thoughts. I did pull weight forward, but [not] quite all the way to amidships.

Ended up moving the new battery forward and into the SUPER SPORT storage box. With the change to a four-stroke-power-cycle engine I no longer needed an external oil reservoir. I left the on-deck fuel tank in the stern, but moved it to the Starboard side to compensate for propeller torque trying to tilt the boat to Port. (Thanks to jimh for advice there).

Those changes opened up the stern area of the cockpit on the Port side, so the swim platform will be mounted on Port.

Fig. 1.

IMG_1100.jpeg (184.74 KiB) Viewed 21628 times

Fig. 2.

IMG_1097.jpeg (130.7 KiB) Viewed 21628 times

The measurements were marked up thanks to Chuck Anderson. The swim platform will be installed soon

[jimh]

You might want to rig the fuel tank and its fuel hose so the tank can be moved to the Port side if the boat seems to prefer that position for neutral trim in some cases. Think of the fuel tank as a sort of moveable ballast.

[davidB01]

Thank you Jim. Good thought. I get the boat back in two days, and I will see where the hull sits, and how it rides.

[davidB01]

Below is [a photograph] of the installation intended for others owners of a 15-foot hiull that are considering [mounting a swim platform on the transom].

Fig. 3. The newly installed swim platform.

swimPlatform.jpg (39.49 KiB) Viewed 21534 times

The swim platform was installed on the Port side, and the new fuel tank was installed on the Starboard side. The hull still has a lean to Port, so next summer I may try the moving the battery to [the Starboard side] from its new location inside the storage box. Per Jim’s suggestion, I do have the option of moving the fuel tank to center or Port if we want to.

I am very happy with results, as I think it will make this more fun for the kids for skiing and swimming, and also more fun for me. The swim platform is for safety should if I ever fall out of the boat.

Thanks to Ray Martin who immediately answered a few mounting location questions. For those adding a platform here are three notes:

• use Ray Martin’s measurements, but ensure you check that your engine, turned to the stop, does not hit the back inside corner of the platform. I moved [the platform] a more outboard to ensure clearance with the new engine when fully turned to Port. That said, don’t go so far that the top outside bolt will be too far into the port transom-to-side “curve” for the specialized bolts that he supplies.
• my decision was to mount [the swim platform] on Port side, especially with the newly cleared space behind the the seat on Port-side, the swim platform rails could be swapped, and the platform mounted just as easily on the Starboard side. Ray ships [the platform] in Port-side-mounting configuration as this is the typical install, but it would have been less than 30 minutes bench work to make it the mirror image;
• [to get the sim platform] level is harder than I thought. With Ray’s help, I first leveled the boat on the trailer to give reference, located and clamped the inside top bracket to the recommended position, and adjusted the outboard mounting bracket so the platform was level and drilled holes from there (after checking and adjusting the side-to-side position above).

Thanks to all who shared thoughts and ideas

[jimh]

Q2: is there any interference between the swim platform and the engine midsection and lower unit when the engine is turned for hard to Port?

As seen in Figure 3, the clearance looks rather tight.

[davidB01]

Q2: is there any interference between the swim platform and the engine midsection and lower unit when the engine is turned for hard to Port?

Yes, it is tight. But there is no interference . We noticed that there was [interference between the engine and the platform] in the dry fit, and adjusted. See the first of the three installation comments above.

Our starting point was the location of the same swim ladder that Chuck Anderson had installed on his 1988 Super Sport. I don’t know if he has interference, but he so carefully crafted that boat, I doubt it. We had to adjust just a bit outboard from there so as not to interfere. We were just at the limit where the outboard bolts by Martin Marine would have been too short had we gone further outboard with the mounting position of the swim platform

[What accounts the difference [in clearance of the engine and swim platform between my boat and the boat owned by Chuck Anderson]? My suspicions are as follows.

• my engine is a Tohatsu 60 and his engine was a Yamaha 70, so the shape of the transition between upper engine and lower unit may be different. On the Tohatsu, it is very curved in that section. The only interference [the might occur on my boat] would have been when the engine was fully trimmed down.
• Chuck is using a set-back jack plate which pushes the engine farther aft and that would allow more clearance [when the engine] fully turned to port; and
• effectively the engine [on Chuck's boat] is mounted quite high as the jack plate is mounted three-holes up on the transom and the engine is four-holes-up on the jack plate, as Chuck wanted to be able to run very shallow. Currently, the Tohatsu engine is mounted three-holes-up, and it could go up one more hole;
• I have no idea where the steering stops are on other boats compared to where the steering stops are on the new steering system I just put in.

I also suspect the angle of my photo contributes to it looking tight

So, the swim platform fits fine post-adjustment, but every engine and setup may be different. I included this as my first caution as I wanted anyone else to ensure they check, as I did, to ensure no interference

[jimh]

I also suspect the angle of my photo contributes to it looking tight

Yes, I agree. In retrospect, the small size of the photograph and the unusual high-overhead view made it look like there was going to be interference.

Thanks for the further clarification. I did not read your initial remarks with sufficient care to catch you comment about interference on the first reading.

The bent tubes that make the support frame for the swim platform are interesting because the upper attachment point of the tubes to the transom will be in tension and the lower attachment point will be in compression. This raises the question:

Q3: are the upper support tubes through-bolted at their attachment to the transom?

[davidB01]

[The swim platform mounting tubes] are through-bolted with all the hardware (which includes some very odd “bent” bolts that match the curve of the transom for the outer Port locations) supplied with the platform from Martin Marine; everything fit perfectly.

Fig. 4. Details of swim platform and engine mounting bolts on inboard face of the transom.

transomMountingBoltsDetails.jpg (68.09 KiB) Viewed 21466 times

Note the upper and lower engine mounting bolt backing plates. These are “harpoon” plates also from Ray Martin. The are machined aluminum, but I chose to highlight the harpoons and outer edges with as close to Boston Whaler red as I could get, covered by clear coat.

Also, this photograph is taken from a better angle to show the clearance to the engine. As noted, it is tight, but just makes it with this particular engine configuration and positioning. In this angle, it looks like the steering arm is also interfering. It is not. Several inches of clearance

David

[jimh]

Figure 4 shows very nice engineering and details.

[Tom Hemphill]

I observe there are stanchions on the inside of the transom for mounting an all-around light on a pole. The pole could be in the way of people using the swim ladder, and also mistaken by them for a hand-hold.

[Phil T]

I agree with Tom.

Move the stern light to the starboard side.

[jimh]

For some reason on the 15-foot hull the wiring for the combined sidelights lamp at the bow was run down the Port side, and this also resulted in the white all-round lamp being installed on the Port side. The reason may be the expectation that mechanical cable steering would be used.

The typical steering used was a mechanical cable steering that routes through the engine tilt tube. The path of that cable may not permit the white all-round lamp dual mounting brackets to be located on the Starboard side of the transom. However, as shown in Figure 2 (above) on this particular installation there may be sufficient room to move the lamp to the Starboard side, as the steering cable seems to be routed in a manner to permit the two brackets to be installed.

The lamp mounting brackets use four screw fasteners, so if you were to move the lamp to a new location, there will be four holes to fill and top coat with gel coat matching resin.

A more practical consideration: the white all-round pole lamp only needs to be installed and illuminated in darkness while the boat is underway. The conflict with swimmers attempting to come aboard from the water in darkness may not occur very often (if ever). When not required to be illumated, the pole lamp could be stowed.