Springfield Mainstay adjustable boat-seat pedestals come in different heights and with different seat mounts. A shorter post is not necessarily a direct substitute for a regular-height model, and a locking swivel is not the same assembly as a locking slide and swivel. This chart compares four exact Springfield 2⅜-inch Mainstay retail packages so you can match the installed seat height, mount function and original part number.

Check the original pedestal before replacing it

Measure the usable heightCompare the original seat's minimum and maximum installed heights with the manufacturer's adjustment range. Regular-height and short versions have different limits.
Check the seat mountThe swivel-only mount allows seat rotation. The slide-and-swivel assembly additionally provides fore-aft positioning. Identify the actual locking Trac-Lock mount MPN.
Confirm the deck installationThese packages use a 2⅜-inch pedestal and 9-inch round anodized base. Verify the original mounting footprint, fasteners and deck reinforcement before replacement.
Do not mix seat-pedestal systems by diameter alone. Springfield's 2⅜-inch Mainstay family is different from its 2⅞-inch heavy-duty and removable-pedestal families. A matching post diameter does not guarantee a compatible base or locking mount. All four exact packages below are classified by Springfield as ABYC H-31 AD, but the boat's complete seating installation must still satisfy its applicable requirements.

Springfield 2⅜-inch Mainstay height and mount chart

All dimensions are in inches. Each exact retail package has a 9-inch round base, anodized aluminum post and air-powered height adjustment using a 500-newton cylinder. The seat-mount numbers listed are Springfield's specified included mounts, not generic replacement interchange numbers.

MPN Height range Family Included mount Mount MPN Product
1250100-L1 14–20 in Regular height Locking Trac-Lock swivel 3100031-LAR1 View
1250150-L1 14½–20½ in Regular height Locking Trac-Lock slide and swivel 3100531-LAR1 View
1250200-L1 12–15½ in Short Mainstay Locking Trac-Lock swivel 3100031-LAR1 View
1250250-L1 12½–16 in Short Mainstay Locking Trac-Lock slide and swivel 3100531-LAR1 View

Compare the four Mainstay pedestal packages

The product photos and links below connect to the matching UsedRVParts listings. Select by exact MPN and measured seat height; do not rely on the appearance of the pedestal alone.

Mainstay seating questions

What's the difference between 1250100-L1 and 1250150-L1?

1250100-L1 adjusts from 14 to 20 inches and includes a locking swivel. 1250150-L1 adjusts from 14½ to 20½ inches and includes a locking slide-and-swivel assembly. The second model is not simply a different package of the first.

Which Springfield models have shorter heights?

In this group, 1250200-L1 adjusts from 12 to 15½ inches with a locking swivel. 1250250-L1 adjusts from 12½ to 16 inches with a locking slide-and-swivel mount.

Do all four Mainstay packages include a seat mount?

Yes. These four manufacturer-designated packages include their specified locking Trac-Lock swivel or slide-and-swivel assembly. The actual boat seat itself is separate.

Can a 2⅞-inch Mainstay pedestal be installed in the same base?

Do not assume so. The 2⅞-inch heavy-duty Mainstay uses a different post construction. Compare the original system and deck mounting requirements with the exact manufacturer documentation.

Does ABYC H-31 AD approval make the pedestal suitable for every helm?

No. The ABYC classification is one component of seating selection. Installation location, fastening strength, deck reinforcement and vessel-specific requirements must also be verified.

Follow Springfield's current installation instructions and the boat manufacturer's seating requirements. Inspect pedestal locks and base fasteners before operating the vessel.

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