With new tools.

• No-clip mode: enables the vanilla spectator mode, with items in the inventory to quit or to enable/disable night vision.
  
  The no-clip menu – left: night vision; right: go back to reality (disables no-clip mode)
• Diving Suit: equips the spectator with Depth-Strider-III boots.

With new toggles.

• tools.tools.glowEffectIfActive (enabled or not – see below).
• tools.tools.speed (enabled or not).
• tools.tools.nightVision (enabled or not).
• tools.tools.divingSuit (enabled or not).
• tools.tools.noClipMode (enabled or not).

With new effects.

• Glow (enchantment-like) effect on the currently active tools (for the speed and the diving suit, useless for the night vision because the item changes).

With a new menu.

I'm open to any suggestion or improvement on this.

Glow: c5f4507 & c425784

Wow, very fancy! Love the glow effect.

New toggles: 7b7d4f6
New layout for existing tools: 77081c7
Diving suit: e9b2014

Well... a Bukkit blocking bug.

I'll use a command to go out of the no-clip mode, and change that to an inventory GUI when this bug will be fixed.