diff --git a/prototyping/coordinate_systems.jl b/prototyping/coordinate_systems.jl
new file mode 100644
index 0000000..e10fe76
--- /dev/null
+++ b/prototyping/coordinate_systems.jl
@@ -0,0 +1,51 @@
+
+abstract type Handedness end
+struct NotHanded <: Handedness end
+abstract type HasHanded end
+struct RHand <: HasHanded end
+struct LHand <: HasHanded end
+
+abstract type CoordinateType end
+
+@kwdef struct Rectangular3D{H <: HasHanded} <: CoordinateType
+    x::Float64 = 0.0
+    y::Float64 = 0.0
+    z::Float64 = 0.0
+end
+
+struct Cylindrical3D{H <: HasHanded} <: CoordinateType
+    r::Float64 = 0.0
+    θ::Float64 = 0.0
+    z::Float64 = 0.0
+end
+
+struct Spherical3D{H <: HasHanded} <: CoordinateType
+    ρ::Float64 = 0.0
+    θ::Float64 = 0.0
+    φ::Float64 = 0.0
+end
+
+struct HorizontalPolar2D{H <: HasHanded} <: CoordinateType
+    r::Float64 = 0.0
+    θ::Float64 = 0.0
+end
+
+struct VerticalPolar2D{H <: HasHanded} <: CoordinateType
+    r::Float64 = 0.0
+    φ::Float64 = 0.0
+end
+
+struct Spherical2D{H <: HasHanded} <: CoordinateType
+    θ::Float64 = 0.0
+    φ::Float64 = 0.0
+end
+
+struct Vertical{H <: HasHanded} <: CoordinateType
+    z = 0.0
+end
+
+struct Horizontal{H <: NotHanded} <: CoordinateType
+    r = 0.0
+end
+
+CoordinateType(::Function) = Rectangular3D{LHand}()
diff --git a/prototyping/environmental_profiles.jl b/prototyping/environmental_profiles.jl
new file mode 100644
index 0000000..73b2754
--- /dev/null
+++ b/prototyping/environmental_profiles.jl
@@ -0,0 +1,85 @@
+## Coordinate Handedness
+abstract type Handedness end
+
+struct UnHanded <: Handedness end
+
+abstract type IsHanded <: Handedness end
+
+struct RHand <: IsHanded end
+struct LHand <: IsHanded end
+
+## Coordinate System
+abstract type CoordinateSystem end
+
+struct Rectangular3D{H <: IsHanded} <: CoordinateSystem end
+struct Cylindrical3D{H <: IsHanded} <: CoordinateSystem end
+struct Spherical3D{H <: IsHanded} <: CoordinateSystem end
+
+struct HorizontalPolar2D{H <: IsHanded} <: CoordinateSystem end
+struct VerticalPolar2D{H <: IsHanded} <: CoordinateSystem end
+struct Spherical2D{H <: IsHanded} <: CoordinateSystem end
+
+struct Vertical{H <: IsHanded} <: CoordinateSystem end
+struct Horizontal{H <: UnHanded} <: CoordinateSystem end
+
+struct Constant{H <: UnHanded} <: CoordinateSystem end
+
+## Coordinate Transformations
+
+
+## Modelling Abstractions
+struct Model{M} end
+Model(M::Symbol) = Model{M}()
+
+abstract type OceanSonarModel <: Function end
+
+(OSM where {OSM <: OceanSonarModel})(M::Symbol, args...; kw...) = OSM(M |> Model, args...; kw...)
+
+abstract type ProfileFunction <: OceanSonarModel end
+
+abstract type ProfileFunctor <: OceanSonarModel end
+
+function (profile_functor::ProfileFunctor)(M |> Model, centre::Real...; pars::Real...)
+    profile_functor
+end
+
+## Model Definition
+struct SoundSpeedFunctionType <: ProfileFunction end
+
+const sound_speed = SoundSpeedFunctionType()
+
+sound_speed(::Model{:Homogeneous}; c::Real) = c
+
+CoordinateSystem(::SoundSpeedFunctionType, ::Model{:Homogeneous}) = Constant{UnHanded}()
+
+function sound_speed(::Model{:Munk}, z::Real; ϵ::Real = 7.37e-3)
+    z̃ = 2(z/1300 - 1)
+    return 1500(
+        1 + ϵ * (
+            z̃ - 1 + exp(-z̃)
+        )
+    )
+end
+
+CoordinateSystem(::SoundSpeedFunctionType, ::Model{:Munk}) = Vertical{LHand}()
+
+## Model Type
+struct SoundSpeed{M, ProfileFunctionType} <: ProfileFunctor
+    model::Model{M}
+    profile::ProfileFunctionType
+    
+    function SoundSpeed(model::Model{M}, centre) where {M}
+        profile()
+    end
+end
+
+function (cel::SoundSpeed)(::Type{<:CoordinateSystem}, args...)
+
+end
+
+## Model Instantiation
+sound_speed = SoundSpeed(:Munk, centre)
+
+## Model Usage
+
+sound_speed()
diff --git a/prototyping/sonar_modelling.jl b/prototyping/sonar_modelling.jl
new file mode 100644
index 0000000..0cef2bb
--- /dev/null
+++ b/prototyping/sonar_modelling.jl
@@ -0,0 +1,222 @@
+## Symbols
+(
+    c = ("Sound Speed", )
+)
+
+## Modelling
+struct Model{M} end
+Model(M::Symbol) = Model{M}()
+
+abstract type ModellingType <: Function end
+
+(mt::ModellingType)(M::Symbol, args...; kw...) = mt(M |> Model, args...; kw...)
+
+abstract type ProfileFunctor <: ModellingType end
+
+(PF where {PF <: ProfileFunctor})(M::Symbol, args...; kw...) = PF{M |> Model}(args...; kw...)
+
+## Traits
+abstract type Handedness end
+struct NotHanded <: Handedness end
+abstract type HasHanded end
+struct RHand <: HasHanded end
+struct LHand <: HasHanded end
+
+abstract type CoordinateType end
+
+### 3D
+struct Rectangular3D{H <: HasHanded} <: CoordinateType end
+
+struct Cylindrical3D{H <: HasHanded} <: CoordinateType end
+
+struct Spherical3D{H <: HasHanded} <: CoordinateType end
+
+### 2D
+struct HorizontalPolar2D{H <: HasHanded} <: CoordinateType end
+
+struct VerticalPolar2D{H <: HasHanded} <: CoordinateType end
+
+struct Spherical2D{H <: HasHanded} <: CoordinateType end
+
+### 1D
+struct Vertical{H <: HasHanded} <: CoordinateType end
+
+struct Horizontal{H <: NotHanded} <: CoordinateType end
+
+### 0D
+struct Constant{H <: NotHanded} <: CoordinateType end
+
+CoordinateType(::Function) = Rectangular3D{LHand}()
+
+verticalsignchange(OldHand::H, NewHand::H) where {H <: HasHanded} = 1
+verticalsignchange(OldHand::OH, NewHand::NH) where {OH <: HasHanded, NH <: HasHanded} = -1
+
+function convertcoordinates(::VerticalPolar2D{OldHand}, ::Vertical{NewHand}, r::Real, z::Real) where {OldHand <: HasHanded, NewHand <: HasHanded}
+    return (
+        verticalsignchange(OldHand, NewHands) * z,
+    )
+end
+
+## Profiles
+abstract type ProfileFunction <: ModellingType end
+
+struct SoundSpeedProfileFunction{M} <: ProfileFunction end
+
+const sound_speed_profile{M <: Model} = SoundSpeedProfileFunction{M}()
+
+function sound_speed{Model{:Munk}}(::Vertical{LHand}, z::Real; ϵ::Real = 7.37e-3)
+    z̃ = 2(z/1300 - 1)
+    return 1500(
+        1 + ϵ * (
+            z̃ - 1 + exp(-z̃)
+        )
+    )
+end
+
+##
+struct SoundSpeed{M} <: ProfileFunctor
+    model::Model{M}
+    profile::Function
+
+    function SoundSpeed(model::Model{M}; pars...) where {M}
+        profile
+        new{M}(model, profile)
+    end
+end
+
+CoordinateType(::SoundSpeed{:Munk}) = Vertical{LHand}()
+
+function (c::SoundSpeed{M} where {M})(input_coordinate_type::CoordinateType, coords...; pars...)
+    c.profile(
+        CoordinateType(c),
+        convertcoordinates(
+            input_coordinate_type,
+            CoordinateType(c),
+            coords...
+        )...;
+        pars...
+    )
+end
+
+function sound_speed(::Model{:Munk}, ::Vertical{LHand}, z::Real; ϵ::Real = 7.37e-3)
+    z̃ = 2(z/1300 - 1)
+    return 1500(
+        1 + ϵ * (
+            z̃ - 1 + exp(-z̃)
+        )
+    )
+end
+
+struct ReflectionCoefficient{M} <: Function
+    model::Model{M}
+end
+
+## Containers
+mutable struct Medium
+    c::SoundSpeed
+end
+
+mutable struct Interface
+    z::Depth
+    R::ReflectionCoefficient
+end
+
+mutable struct Environment
+    surface::Interface
+    bottom::Interface
+
+    atmosphere::Medium
+    ocean::Medium
+    seabed::Medium
+end
+
+mutable struct Scenario2D
+
+end
+
+mutable struct Scenario3D
+
+end
+
+## Computations
+abstract type Config end
+
+struct BeamConfig <: Config
+
+end
+
+struct Beam
+    path
+    pressure
+
+    Beam(::Model{:Ray})
+    Beam(::Model{:Hat})
+    Beam(::Model{:Gaussian})
+end
+
+struct Trace2D <: AbstractVector
+    beams::Vector{<:Beam}
+
+    Trace2D(::Model{:})
+end
+
+struct Trace3D <: AbstractArray
+    beams::Vector{<:Beam}
+
+    Trace3D(::Model{:})
+end
+
+struct Propagation2D <: AbstractMatrix
+    positions
+    pressure
+
+    Propagation2D(::Model{:Trace2D}) = new()
+    Propagation2D(::Model{:Parabolic}) = new()
+end
+
+struct Propagation3D
+    r
+    z
+    θ
+    p
+
+    Propagation3D(::Model{:Trace2D}) = new()
+    Propagation3D(::Model{:Trace3D}) = new()
+end
+
+struct Performance2D
+    r
+    z
+
+    SL
+    PL
+    TS
+    NL
+    AG
+    RL
+    SNR
+    DT
+    SE
+    POD
+
+    Performance2D() = new()
+end
+
+struct Performance3D
+    r
+    z
+    θ
+
+    SL
+    PL
+    TS
+    NL
+    AG
+    RL
+    SNR
+    DT
+    SE
+    POD
+
+    Performance3D() = new()
+end
diff --git a/prototyping/sonar_modelling2.jl b/prototyping/sonar_modelling2.jl
new file mode 100644
index 0000000..f7da15d
--- /dev/null
+++ b/prototyping/sonar_modelling2.jl
@@ -0,0 +1,62 @@
+## Modelling Abstractions
+abstract type OceanSonarModel <: Function end
+
+## Computations
+struct BeamConfig <: Configuration
+
+end
+
+struct Beam
+    path
+    pressure
+
+    Beam(::Model{:Ray})
+    Beam(::Model{:Hat})
+    Beam(::Model{:Gaussian})
+end
+
+struct Trace <: AbstractArray{<:Beam, 2}
+    beams::AbstractArray{<:Beam, 2}
+
+    Trace(model::Model{M}) where M = new() # inherits models from `Beam`
+end
+
+struct Propagation
+    r
+    z
+    θ
+    p
+
+    Propagation(::Model{:Trace}) = new()
+    Propagation(::Model{:Trace}) = new()
+end
+
+@kwdef struct PerformanceConfiguration <: Configuration end
+
+struct Performance
+    model::Model{M} where {M}
+    configuration::PerformanceConfiguration
+
+    r::Vector{Float64}
+    z::Vector{Float64}
+    θ::Vector{Float64}
+
+    SL
+    PL
+    TS
+    NL
+    AG
+    RL
+    SNR
+    DT
+    SE
+    POD
+
+    Performance(::Model{:Multistatic}) = new()
+    Performance(::Model{:Bistatic}) = new()
+    Performance(::Model{:Monostatic}) = new()
+end
+
+Configuration(::Type{<:Performance}; opt...) = PerformanceConfiguration(; opt...)
+
+##