Fair Value Measurements - Schedule of Fair Value of assets and liabilities on a Recurring Basis (Details) - USD ($)	Sep. 30, 2026	Dec. 31, 2025
Assets:
Cash held in Trust Account	$ 265,746,288	$ 258,796,563
Recurring \| Level 1
Assets:
Cash held in Trust Account	$ 265,746,288	$ 258,796,563

Represents the fair value of cash and investments in marketable securities maintained in a trust account, typically restricted for a specific purpose, and measured on a recurring basis using fair value inputs.

No definition available.

Name:	BLUW_CashAndMarketableSecuritiesHeldInTrustAccountFairValueDisclosure
Namespace Prefix:	BLUW_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant