Mounting Instructions

You are 100% responsible for mounting the Stern Step correctly and securely just as you would be with a common ladder. If you are not capable of performing this task please take it to your boat dealer or mechanic!

1. Open the Stern Step package and remove the platform and inspect for shipping damage. Remove the 6 bolts holding the mounting bracket and platform sides together as seen here.

2. Remove your existing swim platform from the boat and place upside down on a table or workbench.

Determine whether or not your specific swim platform has a reinforced mounting area for under mount swim ladders or platforms.

3. If your swim platform has a reinforced mounting area you can drill and tap your fasteners. With the reinforced mounting area available you do not need to drill through holes in your platform although we always recommend through bolting for strength and consistency of mounting. We always suggest through bolting but if you are going to tap we suggest a 3/16” hole with a 1/4” STAINLESS lag bolt.

4. Make sure the bottom surface( now facing up at you) mounting area of your swim platform is flat with no fiberglass bumps or bulges taller than 1/8 of an inch. If this area has fiberglass bumps, ridges, or bulges you will need to sand those flat. Be sure to only sand extra fiberglass resin bumps and do not go below the level surface of the fiberglass.




5. Use the mounting bracket as a template and place it 1 inch from the aft edge of your swim platform if possible. The mounting bracket must be within 3 1/2 inches of the aft edge or slide out will not extend correctly.

6. Mark your drilling points using the holes already cut into the stainless steel mounting bracket. You must use at least four fasteners on the left and four on the right hand side of the mounting bracket. It is best to use the holes furthest left and furthest right if possible. The mounting holes you use must be in contact with the mounting surface with no gaps or voids. You must use a minimum of 4 fasteners per side as shown here.


7. After marking your drill points you must use a ¼” drill bit to drill through holes all the way through your platform that exit out the top of the platform. If you are using tap Fasteners you will need to drill your hole depth approximately 7/8 of an inch deep using a 3/16” drill bit for the 1/4" by 1 inch fasteners. Make sure to put a depth stop on your drill bit so that you do not drill through your platform if you are using the tap fastener mounting method.

8. After the mounting holes are drilled you will need to clean the bottom surface of the swim platform with acetone and the top surface of the stainless steel mounting bracket with acetone.

9. Insert mounting bolts from the top of the platform all the way through so that they extend out the bottom surface of the swim platform. Apply 3M 4200 Quick Cure Marine sealant in between the mounting bracket and your swim platform underside being sure to apply a bead around each mounting bolt.

10. Place the stainless steel mounting bracket back into position over the exposed mounting bolt. Have a helper hold a wrench in the heads of the mounting bolts while you slowly tighten the nuts onto the bolt. It is sometimes easier to have a helper because you must work on both sides of the platform at the same time. Always lubricate stainless nuts and bolts to prevent “galling” while being installed. Slowly tighten the mounting nuts and bolts in an alternating pattern. 15 ft lb of torque is recommended to prevent over tightening. Impact drills are not recommended. Be very careful not to over tighten stainless steel fasteners to prevent damaging the threads.

11. Slide the remaining section of the Stern Step platform over the mounting bracket sides and reinstall using the six included mounting bolts as shown. Two of these bolts must be used per side in the four mounting holes closer to the rear edge of the existing swim platform. The multiple mounting holes allow the platform sides to slide forward or rearward and allow depth adjustment. The best position would be to have the sides nearly flush with the rear of the boat swim platform as shown.

Mounting In Teak

When mounting in teak you must align the mounting bracket holes with a reinforced double thick section of the teak platform underside as shown in the pictures. You can use the tap method or through bolt method outlined in section 7. If none of the mounting bracket holes line up with a double thick teak reinforcement then you must use teak filler spacers and use the through bolt method.