Adjustable length telescoping dilator

A sequential dilator assembly for a vessel;

• the sequential dilator assembly comprising:
• a first dilator segment at least partially nested in a second dilator segment that is at least partially nested within a third dilator segment, wherein the first dilator segment can be axially moved distally relative to the second dilator segment when nested within the third dilator segment, and where the first dilator segment can be releasably locked with the second dilator segment into either a first compact locked configuration or a first extended locked configuration;
• and
• where the second dilator segment can be axially moved distally relative to the third dilator segment independent of whether the first dilator segment and the second dilator segment are in either the first compact locked configuration or the first extended locked configuration, and where the second dilator segment can be releasably locked with the third dilator segment into either a second compact locked configuration or a second extended locked configuration.