Employ internal shock cords to hold down the lid. Advantages: 1) They can apply more force to get the proper curve into the hatch. 1') Hence they seal out water better. 2) You can cut and finish the inside of the hatch combing and lip more easily with the deck off the boat. 3) Cleaner deck.

Disadvantages 1) cleaner deck: you can't get double duty as a paddle park from your hatch hold downs. 2) more difficult to hook into hooks on the underside of the hatches.

All things considered, I prefer them to other hatch hold down methods.

Etienne Muller has photos in his facebook page

https://www.facebook.com/photo.php?fbid=679858415408308&set=a.615556978505119.1073741828.100001524683106&type=3&theater