Sea-Dog's stainless rail base fittings are not all interchangeable. Check whether the existing mounting plate is round or rectangular, whether the tube is 7/8 inch or 1 inch in outside diameter, and whether the socket is a 60° or 90° style. These six part numbers provide a practical identification reference for replacing a rail base.
Identify the base before the socket
Three flat-head mounting points. The 7/8-inch versions in this guide use a 2-5/8-inch diameter base; the 1-inch version uses 2-3/4 inches.
Four flat-head mounting points. Dimensions vary with the angle and tubing size; compare the complete footprint rather than the number of holes alone.
Shape symbols illustrate the two mounting-flange styles only. They are not scale drawings or drilling templates.
Sea-Dog stainless rail-base identification chart
Manufacturer display-packed numbers carry the -1 suffix. Match the original tubing and the base mounting surface.
| MPN | Base shape | Socket angle | Tube O.D. | Base footprint | Mounting fasteners |
|---|---|---|---|---|---|
| 280600-1 | Round | 60° | 7/8 in | 2-5/8 in diameter | 3 × #10 flat-head screws |
| 280601-1 | Round | 60° | 1 in | 2-3/4 in diameter | 3 × 1/4-in flat-head screws |
| 280900-1 | Round | 90° | 7/8 in | 2-5/8 in diameter | 3 × #10 flat-head screws |
| 281600-1 | Rectangular | 60° | 7/8 in | 1-3/4 × 3-1/16 in | 4 × #10 flat-head screws |
| 281900-1 | Rectangular | 90° | 7/8 in | 1-11/16 × 3 in | 4 × #10 flat-head screws |
| 281901-1 | Rectangular | 90° | 1 in | 1-7/8 × 3-3/16 in | 4 × 1/4-in flat-head screws |
Dimensions are manufacturer nominal measurements in inches. FH means flat-head. The screw sizes listed are fastener specifications, not hardware included in the package.
Check the old rail before replacing the fitting
Measure the tube outside diameter with calipers, inspect the original fastener holes and look for corrosion around the mounting surface. A 7/8-inch fitting is not a replacement for a one-inch socket. Confirm whether a 60° slope or upright 90° angle is needed.
For example, 280600-1 and 280601-1 are both 60° round bases, but take different tubing diameters and screw sizes. Likewise, 280900-1 and 281900-1 both accept 7/8-inch tube at 90° but have different base shapes and mounting patterns.
The manufacturer's guidance specifies a 1/8-inch Allen wrench for set screws. Inspect any reused tubing and use appropriate corrosion-resistant mounting hardware; do not assume existing screws are reusable.
Find the exact Sea-Dog replacement
Open the exact part number to check the current listing and availability.
Sea-Dog 280600-1
Identify the 2-5/8 in diameter base and 60° socket. 7/8 in outside-diameter rail.
Check part details and availability
Sea-Dog 280601-1
Identify the 2-3/4 in diameter base and 60° socket. 1 in outside-diameter rail.
Check part details and availability
Sea-Dog 280900-1
Identify the 2-5/8 in diameter base and 90° socket. 7/8 in outside-diameter rail.
Check part details and availability
Sea-Dog 281600-1
Identify the 1-3/4 × 3-1/16 in base and 60° socket. 7/8 in outside-diameter rail.
Check part details and availability
Sea-Dog 281900-1
Identify the 1-11/16 × 3 in base and 90° socket. 7/8 in outside-diameter rail.
Check part details and availability
Sea-Dog 281901-1
Identify the 1-7/8 × 3-3/16 in base and 90° socket. 1 in outside-diameter rail.
Check part details and availabilityOther deck hardware references
UsedRVParts viewing and pickup in Kelowna are by appointment.