These dirks would have been carried by Royal Navy as well as merchant marine officers, even, rather more rarely, by army officers. This classic dirk has a whalebone haft (which, at first glance, might appear to be of walrus ivory, but on closer inspection is definitely whale bone) and iron mounts. The style of hilt, pommel and grip dates it.

The hilt could be Dutch or French, the use of tortoiseshell having been introduced to Europe in the late 17th century, probably through Dutch colonial connections. The mid 18th-century German blade (26" long) would have replaced an earlier, shorter, straight, double-edged blade (broken?), probably to enable the weapon's use as a naval hanger.

This is likely to have been made towards the end of the American Revolutionary War (Peace of Paris, 1783) or during the early part of the Napoleonic Wars (starting 1793). This would have been carried by an RN officer or HEIC naval officer, and this example is interesting in having a particularly long (approx 26") blade.

This is the classic Forestry cutlass worn by senior Foresters (denoted by the ivory grip and the gold/green knot) across Europe from the early 18th century onwards. They continued in use through the Weimar era and Third Reich, only latterly losing the by-knife. Lower ranks wore cutlasses with a stag horn grip and a plain green knot.

This is a classic Ernst Pack dress bayonet, with no maker's mark, but the 'signature' screw bolts which no other maker used. The original owner must have been in a heavy artillery unit, as suggested by the obverse blade etching. These weapons were normally only worn when off duty, but in uniform.