XL Shaft Only – Why Every Model Requires Extra Long Outboards?

Meta Description: All our aluminum RIBs require XL (extra long) shaft outboards – 25 inches. Learn why standard or long shafts cause cavitation, poor fuel economy, and dangerous handling.

Target Keywords: XL shaft outboard, extra long shaft vs long shaft, outboard shaft length guide

The Non-Negotiable Rule

Every aluminum RIB we build – from the 520 to the SP1150 – requires XL (extra long) shaft outboards (25 inches / 635mm).

We do not make exceptions. We do not offer "standard shaft" transoms. If your outboard dealer tries to sell you a long shaft (20") or standard shaft (15"), stop them immediately.

Here is why.

What Happens with the Wrong Shaft Length?

If you mount a standard (15") or long (20") shaft on a 25" transom:

If you mount a long shaft on a 15" or 20" transom (not relevant to our boats, but for context):

Lower unit hits underwater obstacles

Excessive drag

Poor handling

The correct shaft length is not optional. It is basic marine engineering.

Why Do Our RIBs Need XL Shafts?

Two reasons:

• Deep deadrise (24°–26°) A sharp V hull places the transom higher relative to the waterline than a flat-bottom boat. The propeller needs to reach deeper water to stay gripped.

• Large tube diameters (530mm–600mm) Our tubes are large and buoyant. They lift the stern higher at rest and at speed. A standard or long shaft prop would be dangerously close to the surface.

Result: The vertical distance from our transom top to the propeller's ideal depth is exactly 25 inches – XL territory.

Compatible Outboard Brands (XL Shaft Models)

All major brands offer XL (25") shaft options on most models above 50HP:

Before buying an engine, confirm: "Is this the 25-inch XL shaft model?" Do not assume.

Shaft Length by Model Summary

What About Jack Plates?

Some boaters ask: "Can I use a jack plate to raise a long shaft to XL height?"

Technically, yes. But we do not recommend it.

Jack plates add stress to the transom

They shift the engine aft, changing the center of gravity

They introduce another failure point

Our advice: Buy the correct shaft length from the start. No compromises.