A pocket monocular may be the answer.

For a given magnification, monoculars are lighter and easier to hold steady, and simpler to use because there is only one set of controls.

Many sailors also appreciate the fact that they can use their other (now spare) hand to hold on to the ship!

• 10x magnification through a 25mm object lens.

• Tough rubberised casing and supplied with a leatherette belt pouch. 4.5" long.