Hatch

From KayakWiki

Hatches are the holes in your boat where you can put cool stuff.

A well made hatch will be absolutely water tight, would never accidently open while the boat is underway, is big enough to push a few large dry bags into, and is convenient and easy to access with cold wet hands.

Many hatches on North American kayaks use straps with buckles to secure the hatch lid and rubber or foam gaskets to seal the water out. British style kayaks use rubber or flexible plastic covers that seal over matching plastic rims mounted on the kayak. Both hatch types have their advantages and disadvantages and with that, quasi-religious wars over which are better.

Even in the dryest hatch it is a good idea to store your items in dry bags.

Any hole in your kayak is a potential problem and attention should be given to make your hatches as secure as possible.

The middle of a long crossing is no place to discover that your folding camp sofa has prevented the hatch lid from fully closing and you have taken on a couple gallons of water.