5.5e / 2024 · 5e / 2014 · Pathfinder 1E · D&D 3.5e

Plate Armor of the Deep

Plate Armor of the Deep lets a heavily armoured warrior move and live underwater without giving up full plate. It is a Pathfinder 1E and D&D 3.5e specific item; neither 5e ruleset uses this exact item as a core SRD entry.

Explore: Magic Armour & Shields · Water · Water Breathing · Tongues

At a Glance

Item	Plate Armor of the Deep
Theme	Full plate built to function underwater
5e status	No direct core item under this name
Pathfinder / 3.5e	+1 full plate; wearer swims as though unarmoured, breathes underwater and can communicate with water-breathing creatures
Best use	Underwater expeditions, flooded ruins and naval campaigns

D&D 5.5e / 2024
D&D 5e / 2014
Pathfinder 1e
D&D 3.5e

5.5e / 2024

No direct core SRD item under this name. A 2024 conversion should define its armour type, AC bonus, underwater movement or check benefits, water breathing and communication abilities explicitly. Do not import Swim-skill or arcane-armour statistics from 3.x.

5e / 2014

No direct core SRD item under this name. A 2014 conversion should use Athletics, swimming-speed and underwater-combat rules rather than the 3.x Swim-skill framework.

Pathfinder 1E

Price: 24,650 gp · Aura: moderate abjuration · CL: 11th · Weight: 50 lb.

This +1 full plate is decorated with wave and fish motifs. Although it remains as heavy and bulky as normal full plate, its wearer is treated as unarmoured for Swim checks, can breathe underwater and can converse with any water-breathing creature that has a language.

Construction: Craft Magic Arms and Armor, freedom of movement, tongues, water breathing; cost 13,150 gp.

D&D 3.5e

Price: 24,650 gp · Aura: moderate abjuration · CL: 11th.

The 3.5e version is also +1 full plate. The wearer is treated as unarmoured for Swim checks, can breathe underwater and can converse with any creature with a language that breathes water.

Construction: Craft Magic Arms and Armor, freedom of movement, tongues, water breathing; cost 17,150 gp plus 600 XP.

Why Plate Armor of the Deep Matters

Heavy armour normally turns water into a major tactical problem. Plate Armor of the Deep reverses that expectation: the wearer keeps full-plate protection while gaining the movement and survival tools needed for an underwater expedition.

Run It at the Table

3.x: treat the wearer as unarmoured for Swim checks, then apply the item’s water-breathing and communication abilities.
5e conversion: use Athletics, swimming speed and underwater combat rules rather than importing the old Swim skill.
Communication: the legacy item allows conversation with water-breathing creatures that possess a language; it is more than a simple breathing charm.

Adventure Use

This armour is a natural gateway into sunken fortresses, drowned cities, shipwreck vaults and hostile coastal waters. It can transform an underwater chapter from a logistical obstacle into a place where the armoured front-line character can operate confidently.