Swivel Seat Base – 15×15 cm

This swivel seat base is designed to provide easy, smooth 360° rotation for a boat seat. It consists of two square steel plates (top and bottom), each 15×15 cm, connected by a central bearing/pivot. When installed, the top plate (attached to the seat) rotates freely relative to the bottom plate (bolted to the pedestal or deck). The standard 15×15 cm size with four corner mounting holes matches the universal bolt pattern of most marine seats and mounts, making installation straightforward and compatible.

The ability to rotate the seat allows the captain or passengers to change their seating orientation effortlessly – a big advantage for onboard communication or scanning the surroundings. For example, the helm seat can be turned toward the cockpit when the boat is at anchor, or a fishing chair can spin toward the rods. During navigation, however, the seat is usually left facing forward for safety. This model (04315) does not include an integrated locking mechanism, meaning the rotation is completely free (some other models have detents or lock positions – this one does not). If needed, external locking pins or mechanisms can be added to hold the seat in a fixed direction.

Strength and durability of this base are high: it's made of thick steel that can support the weight of an occupant and the dynamic loads of a moving boat. The steel is treated with a corrosion-resistant coating – often galvanized or powder-coated – to prevent rust from salty air and water. This ensures a long service life even with constant outdoor use. The base is relatively flat (its thickness is small, around 20 mm), so it adds almost no additional height to the seat setup.

Installing this swivel base is very simple. The top plate has four holes (typically spaced about 130 mm apart) through which it is bolted to the underside of the seat using nuts and bolts. The bottom plate has four corresponding holes that attach to the pedestal or mounting surface. In some designs, the top and bottom plates are riveted together via the bearing (so you might need to rotate the plates 90° to access the top holes, attach the seat, then rotate back to attach the bottom plate). After installation, ensure all fasteners are securely tightened and that the seat rotates smoothly.

Adding this swivel base greatly enhances the comfort and versatility of boat seating. Instead of a fixed seat, you now have the freedom to turn in any direction, which is especially appreciated during leisure or fishing activities. Moreover, installing it is an economical and easy upgrade that provides significant benefits in day-to-day boat use.

• Typical use cases: Under helm seats on powerboats – enabling the skipper to turn and face the crew; under navigator or companion seats – allowing them to swivel into conversations in the cockpit; on fishing fighting chairs – so the angler can rotate to follow the fish or access gear; under folding chairs in the cabin – for flexible seating around a table.
• Compatibility: Compatible with a wide range of seats (virtually all standard seats with roughly 5″ (12–13 cm) square bolt patterns). It can be mounted on fixed stands, pedestals (including the adjustable models 04244 and the universal base 04265-NS), or directly onto any sturdy horizontal surface. It’s also usable outside of boating – for example, for swiveling chairs in vans, tractors, hunting stands, etc., thanks to its standard design.
• Installation & care: Use the provided or recommended stainless steel fasteners. During installation, applying some grease to the bearing will ensure even smoother rotation (if the bearing isn’t pre-lubricated). Periodically check the bolts – though rare, prolonged vibration can loosen them. Care involves mostly keeping it free of salt and dirt – rinse with fresh water after exposure to saltwater to wash out salt from the bearing and surfaces. If you notice any small rust spots on the bolts or plate, clean them off and consider touching up the coating with a corrosion-inhibiting spray.