Action movie 1980s: hang glider over ocean, dives into ocean, finds a plane, scuba divers appear

An action movie probably from 1980s. The main actor (probably skilled in martial arts) stands on the cliff overlooking the ocean, preparing a hang glider. Probably early morning, the sun is low. Runs to the cliff, starts hang gliding over the ocean. After some time lets go of the glider and jumps into the ocean. At a depth of some 5 m spots an airplane, probably fighter plane, dives to it, possibly finds a breathing equipment in the plane cockpit. As he is diving around the plane, enemy scuba divers appear, engage him. He cuts the breathing tube of one of the enemy divers, disabling him.

Sounds very much like Never Say Never Again (1983)
starring Sean Connery as James Bond.
It has very similar underwater sequences and a fighter jet.
Us old folks may remember this as Thunderball (1965)
also with Sean Connery as Bond, but they remade it in 1983,
per your request.

Unfortunately it is not Never Say Never Again (1983), nor Thunderball (1965). Thank you OmegaMan for your reply.

The underwater scenes in both movies are indeed very similar, but the hang glider over the ocean scene in missing from both movies.

The main actor launches from the cliff with the hang glider, then flies low over the ocean. While gliding he is visually searching for the submerged underwater plane, and once he spots it, flies over it, releases the hang glider and falls into the water. Dives to the bottom (breath only, does not have diving equipment), in the plane finds a small air tank and that’s how starts breathing again. At that time enemy scuba divers appear.

(I am reluctant to add the following, as I may be mixing it from another unknown movie around the same time. The movie is maybe set in the Pacific. Martial arts, Jackie Chan like. There may be another scene where the main actor is exercising in the morning, leg center split in the air, with only the feet on two chairs. It’s part of my same memory, but may be another movie around the same time.)