BOAT is passively managed to provide pure-play exposure to the water transportation industry. The index looks for globally-listed companies that derive significant revenue from cargo shipping, dry-bulk shipping, and oil and natural gas transport. Eligible companies must meet minimum investability and liquidity requirements including a minimum market capitalization of $250 million. The resulting portfolio is ranked by market-cap, with the top eight stocks allocated 5% portfolio weight each. Remaining securities are weighted by market-cap, subject to a 4% single security cap and a liquidity cap. The index is rebalanced semi-annually.