Könnte es auch dingis heißen?

Sorry, das Dingi schreibt sich im Englischen wohl Dinghy. Wenn nicht doch die "Dingi"-Schreibweise (auch) gültig ist, paßt es also sowieso nicht.

reparieren Schlauchboote passt nach meinem Geschmack

Es heißt wirklich "ding" und es geht in diesem Zusammenhang um Surfen, daher passt das mit dem Schlauchboot eher nicht.

laut gugel kann man "fix ding" sogar kaufen ;)

"to ding something" ist in etwa "eine Delle reinhauen", glaub ich.

Google einfach "ding scratch surfboard" und/oder "repair ding surfboard".

http://www.surfing4you.com/surfboarddingrepair.php
MINOR DINGS
There are two basic types of minor dings, punctures and fractures. These dings may occur on you board's nose, tail, rail, or flat surfaces. (...)

http://www.surfing4you.com/surfboarddingrepair.php
However when you use it frequently it is just a matter of time before you scratch, ding, or break it.

Hmm. Schramme? Kratzer? Haarriss? Delle? Bin nicht sicher.

http://en.wikipedia.org/wiki/Ding

Ding, in manufacturing, a dimensional defect in a manufactured part's surface, in which the surface is depressed in a very small area and is usually raised in the immediately surrounding area, due to material deformation caused by the (usually inadvertent or accidental) impact of a blunt object, such as a tool or other manufacturing accessory. The defect may be unimportant or may be a critical defect that would cause unacceptable leakage, friction, poor fit, and/or cosmetic unattractiveness in the manufactured product. Detection of dings requires high-definition metrology of the entire critical surface areas of a manufactured part, since occurrence of dings is largely unpredictable as to their cause, frequency or location on the manufactured surfaces.
Ding, jargon in surf culture, especially Californian, damage due to the impact of any object on a fiberglass surf board.

The outer shell covers and protects the EPS from dings and dents.

Verletzung der Oberfläche durch einen kleinen Einschlag Folge: Kitsche, Abrieb, Riss, Furche, kleine Kerbe. Ding - klein, Dent-groß