Updated June 2026
100 Days At Sea Boss Guide
Six major bosses gate progression through 100 Days At Sea's eight islands, each demanding specific gear, class picks, and team coordination before the Day 100 finale. Sand Worm on Desert Island, Ghost Captain on Shipwreck Island, Lava Guardian on Volcano Island, Frost Giant on Ice Island, Kraken in Kraken Zone, and Bermuda Entity on Bermuda Island form the combat spine of Stranded Devs' survival loop. This guide covers location, prerequisites, recommended classes from tier list, gear from weapons and armor, and phase tips. Deep mechanics on boss fights.
Sand Worm — Desert Island
Location: Desert Island (Medium difficulty). Island resources: Scrap Metal, Cactus Water, Sand. Game tip: Bring a ranged weapon.
Sand Worm is the first major boss gate. Ranged damage is mandatory — melee-only loadouts struggle in the burrow-and-strike arena. Recommended classes: Cowboy (+15% ranged, Flintlock Pistol starter), Sharpshooter (+25% ranged, +10% crit), Pirate (hybrid Cutlass + Pistol).
Prep: Craft Flintlock Pistol from crafting before summon if Sharpshooter not unlocked. Crab companion (+5% gun) or Parrot (+7.5% gun) from companions. Stock Medkits and Cactus Water for heat management.
Co-op: one ranged DPS minimum, Medic for sustain optional. Raider accelerates post-boss Scrap Metal farming for Grinder upgrade.
Ghost Captain — Shipwreck Island
Location: Shipwreck Island (Medium). Resources: Iron, Gunpowder, Ship Parts. Best Iron source mid-game.
Ghost Captain tests mixed combat — melee add clears plus ranged weak-point shots during ghost phase transitions. Recommended: Swordsman (+15% attack speed), Battle Buku (+20% melee), Sharpshooter (ranged), Soldier (+15% defense tank).
Prep: Iron Sword and Iron Armor crafting should begin here — Iron gathered on Shipwreck feeds armor before Volcano. Battle Bunny (+20% dodge) helps dodge captain cleaves. Night Lantern useful if fog reduces visibility.
Post-boss: prioritize Iron stockpile for Volcano Island Lava Guardian. Ghost Captain clear unlocks confident Volcano approach per islands route order.
Lava Guardian — Volcano Island
Location: Volcano Island (Hard). Resources: Obsidian, Magma Ore, Fire Crystals. Tip: Need fire resistance and Iron Armor.
Lava Guardian punishes groups without Iron Armor and fire resist food. Environmental fire damage stacks with boss AOEs. Recommended: Fire Mage (+30% fire, AOE Fire Staff), Soldier (tank), Medic (sustain).
Prep: Iron Armor from Shipwreck Iron is non-negotiable. Bonfire warm meals and fire resist prep from raft building raft kitchen. Lava Snail companion (7.5% less hungry) sustains long attempts.
Fire Mage AOE clears Guardian add waves — unlock before Volcano if Pearls allow (80 Pearl cost). See boss fights for laser and slam phase timing.
Frost Giant — Ice Island
Location: Ice Island (Hard). Resources: Ice Crystals, Frozen Fish, Frost Wood. Tip: Cold drains health — bring warm food.
Frost Giant arena combines cold environmental drain with slow heavy attacks. Warm food from Bonfire cooking counters cold tick. Recommended: Sharpshooter (ranged weak points), Soldier (tank), Medic (regen vs cold).
Prep: Cook Frozen Fish for cold-resist buffs. Seagull companion brings food every 120s. Stock Medkits — ten minimum before summon.
Ranged DPS priority over melee — Frost Giant weak points favor Scoped Rifle crits from Sharpshooter (+10% crit). Olympian swim speed helps if arena has water edge hazards.
Kraken — Kraken Zone
Location: Kraken Zone (Very Hard deep sea). Resources: Kraken Ink, Deep Sea Pearls. Tip: Full crew and S-tier weapons required.
Kraken is the co-op apex boss before Bermuda. Multi-phase fight with tentacle adds, dive phases, and surface burst windows. Recommended: Ancient Squid (+25% water abilities), Sharpshooter, Hero, Raider. Four players strongly advised.
Prep: Scoped Rifle tier weapons, full Iron Armor, bulk Medkits. Ancient Squid Tentacle Summon synergizes with water combat. Deep Sea Pearls from zone fund final class unlocks.
Co-op role split per co op strategy: Soldier or Medic anchor, dual Sharpshooter/Pirate DPS, Ancient Squid or Fire Mage flex. boss fights covers tentacle and laser patterns.
Bermuda Entity — Bermuda Island
Location: Bermuda Island (Very Hard endgame). Resources: Ancient Relics, Mystery Crates. Tip: Final storyline — save for last.
Bermuda Entity is the Day 100 finale boss. Multi-phase encounter combining mechanics from prior bosses — ranged bursts, environmental hazards, and endurance checks. Recommended: Hero (+10% all stats), Pirate, Night (+20% night vision), Treasure Hunter (post-fight crates).
Prep: full S-tier gear, all prior boss experience, Mystery Crate stock from Bermuda farming. Redeem remaining active codes from codes before attempt — no mid-fight Pearl shop.
Victory unlocks Day 100 completion and maximizes Ancient Relic drops. Treasure Hunter (+25% chest loot) on Mystery Crates after Entity phases.
Boss Progression Checklist
Before Sand Worm: Flintlock Pistol or Scoped Rifle, basic armor, Medkits.
Before Ghost Captain: Iron Sword, partial Iron Armor, gunpowder stock.
Before Lava Guardian: full Iron Armor, fire resist food, Fire Mage or Soldier.
Before Frost Giant: warm food stock, Sharpshooter or ranged DPS, cold prep.
Before Kraken: co-op team, S-tier weapons, Ancient Squid optional, full Medkits.
Before Bermuda Entity: Hero or balanced S-tier team, Night vision, Mystery Crate prep.
Frequently Asked Questions
How many bosses are in 100 Days At Sea?
Six major bosses: Sand Worm, Ghost Captain, Lava Guardian, Frost Giant, Kraken, and Bermuda Entity across six islands/zones.
Which boss is first?
Sand Worm on Desert Island is the first major boss. Jungle Island and Starter Island have no bosses.
Can I solo the Kraken?
Kraken is designed for co-op with full crew and S-tier weapons. Solo attempts are extremely difficult.
What gear is required for Lava Guardian?
Iron Armor from Shipwreck Island Iron and fire resistance food. Fire Mage class strongly recommended for AOE.
What is the final boss?
Bermuda Entity on Bermuda Island is the final storyline boss before Day 100 completion.