Boat cup holder sizes explained (and why yours feels loose)

Boat Cup Holder Sizes Explained

Most boat cup holders have an internal diameter of 90–93mm, which is considered the standard size in many marine setups.

They’re designed to fit a wide range of drinks, so the fit is often loose—especially with smaller cans or bottles.

How to Measure Your Cup Holder

Measure across the top opening from edge to edge (the internal diameter).

  • Measure the widest point at the top. Avoid the rounded top edge—measure slightly below it where the sides are straight.

  • Use a ruler or tape measure

  • Measure in millimetres (mm)

If your cup holder measures between 90–93mm, it’s a standard marine size.

Why Drinks Feel Loose in Boat Cup Holders

Boat cup holders are designed to accommodate different drink sizes, which means they rarely hold any one drink tightly.

This can cause:

  • Drinks rattling while underway

  • Cups shifting or tipping in rough water

  • Smaller bottles feeling especially loose

How to Fix a Loose Cup Holder Fit

The most effective way to stop drinks moving is to use a cup holder insert.

Instead of relying on a fixed opening, an insert adapts to both the holder and the drink—creating a more secure fit and reducing movement.

Why Docksy Works

Docksy is designed specifically for standard marine cup holders (around 90–93mm), using flexible grips that expand under pressure.

This means:

  • A tighter hold on a wide range of drink sizes

  • Reduced rattling and movement

  • A more secure fit in real boating conditions

If your drinks feel loose in your cup holder, Docksy is a simple, effective way to fix it.

Docksy is currently in testing. Join the waitlist to be first to get access and exclusive launch pricing.

See Docksy at docksy.co.uk